Bovensiepen Builds an 800-HP M5 Gran Turismo for €200,000

Bovensiepen, the Buchloe, Bavaria-based coachbuilder that debuted at Fuori Concorso on Lake Como in May 2025 with the Zagato, has revealed its second model. The 05 GT is a plug-in hybrid Gran Turismo built on the G90 BMW M5, with a full exterior redesign, a titanium Akrapovič exhaust, and a system output of 589 kW — 800 hp — paired with 1,100 Nm of torque. Top speed is 305 km/h, and Bovensiepen claims 0-100 km/h in under 3.6 seconds.

The base price is €198,900 including German VAT, which puts it roughly €50,000 above a standard M5. That gets you the new body, the exhaust system, and a leather interior with the Lavalina-wrapped steering wheel and aluminum shift paddles. If you want the full Lavalina leather cabin that appears in the press photographs — the barrel-dyed cowhide suede that Bovensiepen sources exclusively from farms in southern Germany, Austria, Switzerland, and northern Italy — that costs another €20,000 on top.

A Body Modified by Frank Stephenson

The exterior is entirely new at the front and rear, with reshaped sills running the full length of the car. The front bumper, side skirts, and rear are tied together by a continuous wraparound design line — borrowing the same visual trick from the Zagato — with the line color matched to the exterior paint. The front grille is laser-cut stainless steel. The rear gets an Akrapovič titanium exhaust with four oval tailpipes.

Frank Stephenson, former BMW designer, developed the new design language. Bovensiepen says the process involved Stephenson’s team working directly on the vehicle at the Buchloe facility, not just at a design studio.

One thing to note: the rear doors are unchanged from the standard M5. BMW didn’t widen the door skins when it built the G90, so the widened front and rear bodywork doesn’t carry through at the B- and C-pillars the way it might on a clean-sheet design. Bovensiepen has disguised this as well as you can, but it’s there.

21-Inch Forged Wheels, Pirelli Tires, Eibach Springs

The suspension gets modified support bearings, Eibach springs, and a strut tower brace. Wheels are 21-inch lightweight forged units with twenty milled spokes; Bovensiepen says the spoke count saves weight while the ten double-spoke visual pattern gives the wheel its depth. Custom-developed Pirelli tires are marked with a “BOV” sidewall stamp. Brake calipers carry the Bovensiepen logo and can be color-matched to the body or the design line. The Akrapovič exhaust saves 7.8 kg over the stock system.

Engine software was recalibrated after testing at Papenburg and Nardò, with a revised intake funnel and the larger-flowing exhaust creating the conditions for the power increase. The 800 hp figure is total system output, consistent with how BMW quotes the M5’s PHEV powertrain.

Numbered Plates And Lavalina Leather Inside

Each car gets a numbered production plate. The cockpit carries a handcrafted Lavalina steering wheel with milled aluminium shift paddles as standard. Seat panels, the area around the cupholders, and the iDrive controller surround are leather-trimmed. Seatback panels can be painted in any color at no extra charge, with leather inserts and the 05 GT designation. The full Lavalina interior — where virtually every surface can be specified in any leather and stitching color — is the upgrade that adds the €20,000.

The company will also do Alcantara trunk linings, embossed headrest stamps, and custom embroidery. At 200 cars per year, they have the throughput to actually execute that kind of thing.