While we often come across many interesting vehicles while following certain car auctions, this ultra-low mileage limited edition Buick stands out like a shag on a rock.

The GNX (Grand National Experimental) was built for a single model year back in 1987, this one being car #480 out of 547. After being sold in Arkansas and taken to a Texas dealership to go on display, nobody drove it anymore, hence the 8.5 miles (13.7 km) on its turbocharged 3.5-liter V6 engine.

Not your everyday Regal

Buick built the GNX in partnership with McLaren Performance Technologies/ASC, giving the car an upgraded powertrain, suspension and instrumentation. The previously-mentioned V6 unit was mated to a 4-speed automatic gearbox, while power and torque figures stood at 300 HP (304 PS) and 420 lb-ft (569 Nm).

In order to produce more power, the engine was fitted with a Garrett T3 turbocharger, a larger intercooler and a low-restriction exhaust system. On paper, this car could reportedly cover a 1/4 mile in just 12.7 seconds straight out of the factory, quicker than a Porsche 911 (930) Turbo.

This one in particular even retains its factory protective plastic coverings inside (it has a two-tone black and grey cloth interior), to go with the original window sticker, factory GNX badging, 16-inch alloy wheels with Goodyear Eagle VR50 tires and GNX-branded center caps, among others.

Right now, the car is being auctioned off on Bring a Trailer, where the winning bid will be in excess of $100,000.