This Ford GT Prototype Is the Only One of Its Kind Left. It’s Now up for Grabs.

A car integral to the Ford GT’s post-production development is about to go up for grabs.

A first-generation GT prototype will be auctioned off by Mecum at its upcoming Dallas sale. The example is one of two post-production vehicles used by the automaker and its partners as a test bed to further refine what is now considered one of the finest American sports cars of all time.

This particular GT was built in 2006, two years after production of the heritage model had begun. The car was a hit from the get-go, but test mules were built for use as a “critical testing and validation tool,” according to the listing. These prototypes were used by Ford’s Special Vehicle Team, Ford Racing, and other aftermarket partners. Two of these cars were built, but it is unknown what happened to the second, making this example the only one in circulation.

The prototype’s gorgeous GT40-inspired body is finished in Tungsten topped with silver racing stripes. Despite being a test mule, this example looks identical to the finished customer car down to its forged BBS wheels. This isn’t just true of the interior, either. The two-seater’s cabin is indistinguishable from that of a production vehicle and features a black leather interior and aluminum trim. One difference is an upgraded Pioneer audio system with Bluetooth.

This GT is powered by a mid-mounted supercharged 5.4-liter Eaton aluminum V-8 mated to a six-speed Ricardo manual transmission just like the production-spec examples. But the mill in the prototype has a bespoke ECU that helps boost output from 550 hp and 500 ft lbs of torque to 633 horses and 549 ft lbs of twist. No performance numbers are listed, but the stock version of the rear-wheel-drive vehicle could hit 62 mph in 3.8 seconds and topped out at 205 mph. In addition to the ECU, other upgrades include a Steeda Autosports under-drive supercharger pulley, Borla long-tube headers, and a Ford Performance muffler.

Intrigued by this rare GT? The car will cross the auction block on Saturday, September 7. No estimate has been provided by Mecum, but it wouldn’t be a surprise to see the car eclipse the $500,000 that first-generation GT’s regularly attract on the open market.

Click here for more photos of the 2006 Ford GT prototype.