I have a saying about Isderas: They’re the best and I love them. So you can bet that when news emerged today that of the boutique German automaker’s few machines was headed for the auction block, an alarm bell started ringing in my head. I’m told this isn’t a normal aspect of human existence and not everyone has a built-in Isdera auction alert system, but nevertheless.

Today’s Isdera, soon go to one very lucky buyer, is a 1991 Imperator 108i. The Imperator enjoyed a lengthy production run from 1984 to 1993, and during that time 30 cars rolled out of the company’s Leonberg, Germany factory. It was an evolution of a design first revealed as the Mercedes-Benz CW311 concept in 1978.

Initial Imperators employed Mercedes’ 5.0-liter M117 V8, producing just under 300 horsepower, but by the end of the car’s run that engine was replaced with a 6.0-liter AMG unit churning 390 HP. Although the listing on doesn’t state precisely which engine is in this Imperator — nor does it share any specifications at all — there is a photo of a 5.0-liter badge on the back, as well as copious shots of that engine.

The Imperator has always struck me as one of most unconventionally pretty sports cars of all time. In profile it’s certainly odd — there’s a chunky, elongated shape to it, almost like a stone that’s been chiseled away at, though some of its original form still remains. It shouldn’t work, but it does in that unapologetically ’80s way.

From front to back, this car is rife with defining features rarely seen in supercars then or even now. The windshield and windows extend very far down, but seamlessly meld with the fiberglass body. The right-side exhaust pipes, escaping out two rectangular holes in the sill, tease the Imperator’s sporting purpose. And the slide-back headlight covers are a staple of the time you can’t help but love — though I personally prefer the exposed, circular lamps on older chassis. (Early models also had a periscope rear-view mirror mounted on the roof, rather than the conventional side-mounted ones seen on this example.)

All these elements culminate in a car that is very technical and German, but also kind of dramatic and elegant, too — like the more suave relative. I wouldn’t lavish quite the same praise on the interior; it’s pretty rudimentary, like you’d expect of a small-numbers sports car builder in the ’80s, and it and could certainly use a good cleaning.

The Imperator may not be quite as otherworldly as the one-of-one Commendatore 112i auctioned some months back, but it is core to the Isdera story. Isdera founder Eberhard Schulz conceived the CW311 as a then-modern 300SL successor for Mercedes, complete with gullwing doors, during his tenure at German coachbuilder BB Auto. When Mercedes wasn’t willing to produce the CW311, Schulz took matters into his own hands. And the world was better for it.

The Imperator is due to be auctioned in Monaco on April 23. Bonhams values it between $592,000 and $830,000.