It was at the 2003 Detroit Auto Show where Ford first previewed what it had in mind for its then-upcoming fifth-generation Mustang. The old Fox-body generation was gone, as well as its "New Edge" successor. This time, however, Ford decided to take a far more retro design approach. Before the production version arrived, a concept car debuted that got everyone totally excited. In short, the concept looked amazing but the eventual production Mustang was a bit of a letdown. Once again the styling was toned down.

The fifth-gen Ford Mustang arrived in 2005 and remained on sale until 2014, an impressive lifespan for any modern-day vehicle. Mustang fans certainly welcomed the somewhat old school design, but many simply couldn't forget the stunning concept. It was yet another reminder of one of the often brutal realities of the business. Designers can't always get exactly what they want.

The concept car you're looking at is the very one shown in Detroit that year and now it's for sale at Barrett-Jackson's online auction later this month. It was actually up for sale back in 2016 but now it's time to pass it on to someone else. Now, the first thing you need to know is that it's not street legal. Remember, it's a concept. However, there is a 3.9-liter V8 under the hood that's paired to a five-speed manual gearbox. Ford utilized the then reborn Thunderbird's rear-wheel-drive platform for this project.

The 20-inch wheels and the lowered stance, sadly, didn't make production, but they do prove what could have been possible. Designers clearly spent a great deal of time with the details. For example, there are 13.8-inch vented and cross-drilled Brembo disc brakes pushed towards the corners and lots of beautiful body styling elements. We also like how the rear exhausts are built-in to the rear bumper.

Take note of the sharp accent line running the length of the body just above the rocker panel. There's a showbar with gorgeous billet aluminum trim, which continues throughout the interior where the seats are covered in red and charcoal-colored leather. The four-point racing-style seat belts, instrument gauges, and steering are all noteworthy styling touches.

Despite the fact it can't (legally) be driven, there's no doubt the 2004 Mustang GT Convertible Concept deserves a place in the nameplate's long history. A private collector/fan will no doubt want it in their garage. The price? It's being offered at no reserve but interested buyers should note they'll need to arrange transportation from its current location of Scottsdale, Arizona.