If you haven't yet heard of the Ring Brothers, you may want to look them up. No, they don't build Audis, but their builds are usually incredible and worth a look for any auto enthusiast. That was our thought when we recently watched an episode of Jay Leno's Garage (embedded in this story) about their bonkers carbon fiber bodied 1965 Mustang Fastback and caught an interesting Audi detail.

Even if you're not into muscle cars, the '65 Mustang fastback is one to be aware of. It was the car that Steve McQueen raced around San Francisco in Bullitt, and one of just two muscle cars that Audi Sport factory driver Andre Lotterer has added to his growing car collection. It is an icon, and causes interest when someone as significant as the Ring Brothers build one.

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The nuttiness of course ensues whenever these guys are involved, and this otherwise subtle-looking Ford bears no shortage of nuttiness. All of that bodywork... yup, a subtle widebody made entirely of carbon fiber much like a Singer Porsche 911. Under the hood is a Chevy motor, which will make Ford fan boys get heart palpitations. Also, that Chevy motor is supercharged.

So why is the car on our radar? One reason only really. It's the badges. Check out our header above and you'll spot the carbon fiber adorned supercharged badge that was first fitted to U.S. spec C6 A6 models with the then-new 3.0 TFSI engine. Nowadays the badge is red (not carbon) and goes on cars like the SQ5, S4 and S5.

Want to know more about this car? Watch the episode of Jay Leno's Garage that we've embedded into this story.