For the latest classic car news, features, buyer’s guides and classifieds, sign up to the C&SC newsletter here
There are some things so rare that no one is entirely sure whether they exist, the fine line between extinction and fantasy blurred by the passing of time.
Imagine seeing a Sasquatch lumber through the trees before shooting you a sideways glance and you’ll have some idea how it feels to set eyes on the fabled AMG-tuned 123 wagon.
It couldn’t be more different from the champagne-coloured beater I rode around in as a kid, a workhorse bought for ferrying garden waste to the tip.
This car has none of that easy charm, instead giving off an air of menace as it sits at the back of a gloomy warehouse, its black paint blending into the darkness of its surroundings.
The tale of how this ‘unicorn’ came to be can be traced back to the ’60s, and the engine workshops of Daimler-Benz.
Engineers Hans Werner Aufrecht and Erhard Melcher were hard at work in the development department, fine-tuning the race engine that was destined to grace the 300SE until a change in direction led Mercedes to withdraw from motorsport.
The two were so invested that they continued their work from Aufrecht’s house in Grossaspach, 35km north-east of the factory.
Their determination bore fruit in 1965, when the car’s assault on the Deutsche Rundstrecken-Meisterschaft yielded no fewer than 10 wins in the hands of Manfred Schiek.
Reputations were forged that season, and the following year Aufrecht left the firm to start his own, convincing Melcher to join him in 1967.
From its headquarters in an old mill outside Burgstall, the fledgling AMG began to develop engines for privateer race teams, among them a customer who wanted to campaign a seemingly unlikely machine: his 300SEL.
The pair worked their magic on the big saloon, enlarging it from 6.3 to 6.8 litres and increasing power to more than 400bhp.
The car was so incongruous that it quickly earned the nickname ‘Red Pig’, but its detractors – and AMG’s – were humbled in 1971 when the hulking barge stormed to a class win and second overall at that year’s Spa 24 Hours.
“I worked there during my final year of school, in the summer vacation,” says Hartmut Feyhl, who spent 12 years with AMG before going on to become one of North America’s leading Mercedes tuners.
“The building was very old, with two bays and inspection pits, and big swing doors. There was one mechanic, Hans’ younger brother Friedrich, his father-in-law – who ran around getting parts – and me.
“On the second floor was Melcher, who had an engineering office where he did work for AMG. That wasn’t enough to survive, so he did development for other tuners and teams, making Formula Two camshafts and fettling Ducati engines.
“Everything he touched turned to gold; everything was spot-on and no one could keep up.”
In the years that followed, the firm expanded from race prep to road cars, improving a number of private cars with everything from suspension upgrades to full engine conversions.
By 1976, the company had outgrown the mill and moved to a purpose-built workshop in Affalterbach, a 15-minute drive south towards Stuttgart.
AMG was still small, with no more than a dozen employees on the payroll, and work on customer cars was carried out on an ad-hoc basis, and with little consideration to model continuity.
“Everything was done in-house,” says Feyhl, “but we weren’t making parts to ship out like today. We didn’t have decent brakes, or suspension for that matter.
“If something from a heavier car – sometimes even an armoured car – fitted a lesser model, such as a sway bar or a differential with shorter gearing, then we’d use that.”
“During those early days we made a bunch of special cars with engine conversions,” enthuses Feyl.
And it was while serving as an apprentice, working part-time outside school hours, that he recalls the arrival of the near-mythical 123-series estates: “I remember downstairs, where all the speciality stuff was done, there was a 123 wagon.
“We did two of them – one black and one silver – and I did a couple of jobs here and there, such as bending pipes for the exhausts and headers.”
Given the exclusivity of the AMG estate, and the manner in which it was built, it comes as no surprise to learn that the slab-sided 500TE flew under the radar for much of its life, remaining anonymous until its discovery by US-based AMG fan and film producer Henric Nieminen in 2013.
Acting on a tip-off from a fellow enthusiast, Nieminen bought the tired wagon, which had made the journey from Germany after being bought by a Californian jeweller, and had since been hiding right under his nose in Los Angeles.
The condition of the car was poor, cosmetically rough from a hard life spent under the relentless California sun, but Nieminen immediately recognised the significance of his discovery and began returning it to its former glory – just as he had done with a ‘Widebody’ 500SEC AMG that he chanced upon in Arizona a few years earlier.
The uninitiated may pass the wagon by, writing it off as just another mum’s taxi used to take kids to football practice or to pick up flat-pack furniture, but Nieminen straight away spotted that this was no ordinary TE.
The first clue was the BBS-style wheels, which predated AMG’s calling-card Penta five-spokes that became standard fitment in 1983.
A subtle bodykit provided another nod to the estate’s heritage, as did, upon closer inspection, anti-squat rear suspension, a limited-slip diff and cast-aluminium trailing arms borrowed from a W126 – all unusual (and costly) modifications for a model that more commonly saw service as a cab.
Opening the over-engineered driver’s door revealed further indications that this was an early example of AMG’s work.
The dowdy interior of the standard car was thrown out in favour of supportive Recaro sports seats – date-stamped to match the car’s 1979 build year – and on the dash top a telltale pod was added, which matched perfectly that of a taxi upper console, often used by AMG to house additional gauges.
The whole affair was dripping in soft leather, every surface clad in tan hide like a tobacconist’s padded cell. But the biggest giveaway to the estate’s exclusive breeding comes when you open the bonnet.
Instead of the usual four- or six-pot you expect to find in an S123, which ranged from 2-litre petrol and diesel motors to a 3-litre turbodiesel, the engine bay is almost entirely filled by a hulking 5-litre V8.
The M117 shoehorned into the Mercedes is an early aluminium C107 500SLC unit, as Nieminen uncovered, and further sleuthing revealed that it was never allocated to a particular chassis, suggesting that it didn’t leave Mercedes’ factory under its own steam.
The sledgehammer of an engine is also fitted with trick tubular manifolds, with flanges that match those of contemporary authenticated AMG items; two additional oil coolers in series; and bespoke engine mounts designed specifically for the marriage of the M117 to the 123 shell.
Frustratingly, efforts to verify the 500TE’s authenticity proved fruitless – which was no surprise to those with a passion for early AMGs.
Back then, little thought was given to standardising a product range or providing turn-key solutions.
Without documentation, which is maddeningly thin on the ground, it’s impossible to confirm that the car was converted by AMG in period.
But not even a DNA match is perfect, and all signs point to this car being the genuine article; to recreate it to this degree of accuracy would require nothing short of a time machine.
Despite mounting evidence of its historical significance the 123 had suffered neglect, leading Nieminen to stage an intervention.
In short order, the lifelong AMG enthusiast had stripped the engine, re-cored the radiator and gone to town on the engine bay.
The rolling shell was then sent to a bodywork specialist, who ensured each panel was straight before laying down fresh black paint to match the new five-spoke wheels – a later addition that suit the car. A new air-con compressor was fitted, along with replacement fuel lines, water pump and thermostat.
Nieminen pulled apart the Recaro Ideal-C seats for refurbishment and discovered the date stamp – 6 July 1979.
This suggests that they were fitted not long after the car left the factory, adding weight to the theory that it was converted in its homeland before making the trip to the USA. He then set about finding a replacement for the taxi console, which had been lost.
The rebuild complete, Nieminen enjoyed the car for a number of years, and it even made a television appearance on Top Gear before joining one of Europe’s largest collections of modern classics.
There it has remained since, locked away among hundreds of rarities including several ‘Widebody’ AMGs.
Twisting the key prompts the clicking of fuel pumps and whirring of electromechanical doodads from deep in the engine bay, preceding a guttural bark that echoes around the warehouse as the big V8 catches.
It’s an angry thing, and even at idle the car shakes in anticipation like a racehorse about to be released from its traps, relaxing slightly after being slotted into ‘Drive’.
The four-speed auto is perfectly suited to the wagon; rumbling along at walking pace it could almost pass as a boulevardier – if the boulevard in question is a chain-link-fenced street in South Central LA, with Converse Chuck Taylors swinging by their laces from the telegraph wires.
One glance at this threatening wagon rolling along the block, and even the street-corner dealers would look down at their shoes.
A short drive takes us from the low valleys near Geneva to foothills peppered with sleepy villages. Concrete performance figures are – unsurprisingly – elusive, but it’s safe to say that the V8 is kicking out around 275bhp.
It certainly feels potent: up the sort of gradient that would have Olympic cyclists puffing and blowing, the c1700kg Mercedes wafts effortlessly with just a quick squeeze of the accelerator.
Put your foot to the floor and kickdown takes things up a notch, the rear hunkering down and the squeal of tortured tyres almost drowned out by the bellow from the Sebring sports exhaust. It’s the sort of noise that might come out of Barry White, if you set fire to his trousers.
Further up the rev range the V8 really begins to sing, with an eagerness you don’t expect from such a meaty unit.
During its time in America, the 500TE must have rubbed shoulders with plenty of estates featuring primitive live rear axles and possessing all the dynamism of a wheelie bin.
The Mercedes is different, with firm springs and independent suspension that does a terrific job of keeping the heavy machine planted.
It’s still a long, weighty wagon, but it manages to feel sporty, especially when pressing on along the narrow lanes that criss-cross the hillsides of eastern Switzerland.
After a long afternoon blast, you can’t help but wonder why Mercedes itself didn’t come up with the idea of mating this gem of an engine with its workhorse S123.
It’s unusual to find a car that blends presence, attitude and performance with such astounding practicality, and the fact that this wagon is so scarce only adds to its charm.
Images: Will Williams