Signature Autosports 355 SL: gullwing restomod on SLK 55 AMG

Signature Autosports has sketched a clear path for those who dream of a Mercedes 300SL Gullwing but don’t want the realities of a collector car with a multi-million price tag and a lifetime spent chasing rare parts. Their project is called the 355 SL: on the surface it nods to the iconic 1950s gullwing, while underneath it’s built around a 2014 Mercedes-Benz SLK 55 AMG. The result is a restomod with a timeless silhouette, fewer old-school compromises, and the reassurance of modern reliability.

The best part is that the donor hardware is largely untouched where it matters. Under the hood sits the naturally aspirated 5.5-liter M152 V8 with 421 hp, paired with a 7-speed AMG Speedshift Plus automatic and rear-wheel drive. In other words, this isn’t a showpiece pretending to be fast; it’s a true AMG V8 wearing a different suit. To tighten up the way it drives, it gets adjustable KW coilovers (height/rebound/compression). The rolling stock stays on message too: custom 18-inch three-piece wheels designed for 300SL-style hub caps, shod with Michelin Pilot Sport Cup 2 tires—rubber that hints at real intent, not just curb appeal.

Inside, it’s a deliberate compromise: the cabin is essentially SLK 55, with heated, power-adjustable seats, air conditioning, a modern audio system, and Bluetooth. The trunk is finished in Alcantara, and the familiar button array on the center console unexpectedly comes off as almost futuristic—like a bridge between the 300SL era and the spirit of the SLS AMG. And yes, the headline act is a pair of roof-hinged gullwing doors that bring the spectacle without the stress of owning a museum piece. The overall execution delivers theater with the everyday usability enthusiasts quietly hope for.

Affordable, though, it isn’t. This particular example with around 110,000 km is listed at $299,950. That’s far pricier than a clean SLK 55 (usually closer to $40,000), yet it’s nowhere near the cost of a genuine 300SL, which can climb into the several-million range. In the end, the value equation comes down to how much one prizes the drama and AMG bite over absolute originality.