As you all know by now, I spend an unhealthy amount of time looking that I wish I could own. A lot of the time, I skip right by six figure supercars without even registering them. But occasionally, catches my attention and curiosity. 1989 Isdera Spyder 036i is one of them, and this is a car that gets cooler the more you learn about it.

We’ve about Isdera a lot over the years, and even now the company is still fascinating. Our Raphael Orlove that Isdera is like the European equivalent of Vector. It talks a lot about building cars, but you never see them. In fact, the company doesn’t even publish sales data so true production numbers are unknown.

Isdera is the brainchild of designer Eberhard Schulz. He got his foot in the door of auto design by building his own sports car, the 400 HP 1969 Erator GTE. The car impressed Porsche, and in 1971, the marque hired Schulz on as a designer.

While working for Porsche, Schulz worked his second prototype, a car that evoked the image of the Mercedes-Benz 300 SL. In 1978, he met tuner Rainer Buchmann and the two joined forces to make B&B GmbH & Co Auto KG. Together, they made the second concept come to life as the CW311, a Mercedes-Benz V8-powered concept complete with the Mercedes-Benz star right on the front.

Mercedes-Benz wasn’t convinced and did not move to build the CW311. And in 1982, Schulz left B&B to create Isdera AG to see his ideas hit the road.

As the RM Sotheby’s auction for this vehicle , the first car to come out of the newly-formed company was the Spyder:

An exotic and advanced vehicle that was hand-built to order, it was powered by a 1.8-litre four-cylinder Mercedes-Benz engine. For 1985, Isdera launched the Spyder 033-16, equipped with a more powerful 2.3-litre four-cylinder Mercedes-Benz engine. Two years later, the final iteration of the Spyder was unveiled at the 1987 Geneva Motor Show. Named the Spyder 036i, it was powered by a 3.0-litre inline-six Mercedes-Benz powerplant, producing 217 horsepower. Across the three generations, it is believed no more than 14 Spyders were manufactured—likely due to the 12 months it took to build each car by hand.

These cars feature a tubular steel spaceframe chassis and a body of fiberglass. That aforementioned Mercedes six was situated behind the minimalist cockpit, driving the rear wheels. As Silodrome , getting one of these cars involved calling up Isdera’s CEO to place an order

In 1984, the Spyders would be joined by . This supercar is the CW311 realized in production form. It too has a tubular steel spaceframe but with a roof and firepower coming from a 5.0-liter Mercedes-Benz V8.

This Isdera Spyder 036i left the factory on March 28, 1989. It went on display at the 1989 Geneva Motor Show and is said to have spent most of its life in Germany with its first owner before being sold in 2006.

The previous owner of this 036i took it back to the factory where Isdera performed some modifications:

On 14 July 2011, this example entered Isdera’s factory in Hildesheim, Germany. The exterior of the vehicle was modified, with the front and rear wings flared and then finished in metallic silver. This allowed for the next modification, which was the installation of larger 16-inch alloy wheels, wrapped in Toyo Proxes tyres. Inside the cabin, the Violet interior was stripped out and reupholstered in blue leather, while Recaro Sportster seats were installed and the door cards trimmed in dark blue. It was at the rear of the car where Isdera made the most significant and captivating modification. The old 3.0-litre Mercedes-Benz straight-six was removed, and in its place a 276 horsepower 3.6-litre engine from AMG took its place, representing a 27 per cent increase in power.

If you have the money, this is a neat piece of automotive history and a rare one at that. As mentioned above, this is just one of the 14 known to exist. And while Isdera and is still building however many cars that it does, chances are you’ll never see another on the road.

The auction goes live . For a gauge on what this could go for, another 036i was listed for $255,900 , and it didn’t have factory-added modifications.