This would be the ultimate piece of functioning automotive art.
Audi produces some pretty special cars at the moment, and it's not difficult to find something in the brand's lineup that will impress your friends. You could go for the Audi R8 supercar or blow more than of your mates away at once by taking them for a blast in the RS6 Avant. Alternatively, you could impress them with a museum piece like a Le Mans-winning racer, but if you really want to show off, nothing quite says "I've got more money than I know what to do with" than buying something super rare. And nothing is quite as rare as a one-of-one car like the 532-horsepower Le Mans racer below.
To be clear, this isn't the only Le Mans racer that Audi ever made - there were plenty. No, the R18 TDI Ultra you see before you is truly special because it is the only fully functioning example in private hands (the rest are obviously owned by Audi). See, when a special racecar like this goes up for sale, the ECU is usually removed so that the car can't be run, but this one is different. Why Audi decided to allow this one to escape its grasp is beyond us, but we're glad it's out there.
Some history: The R18 TDI Ultra is the car that took Audi to four of the manufacturer's 13 Le Mans victories from 2011 to 2014. This particular example is built to less complicated non-hybrid spec, but Art & Revs, the establishment facilitating the sale of this car, says that "an ex-Audi Sport engineer will be pleased to accompany the car and support its new owner in racing it." Presumably, one would race such a vehicle in some sort of open class where it would steal the show in amateur motorsport.
This car is chassis #100 and is one of eight cars built to this spec. Two of that original eight no longer exist and this one was never formally raced during the R18 TDI Ultra's time in Le Mans. Instead, it was taken to the track as a backup car. Then in 2013, it was modified to look like a later-spec hybrid model for press photos while the real hybrids were out racing. In 2018, it was fully restored by Audi Sport and returned to its original spec. Apparently, it hasn't moved since, so that 3.7-liter V6 diesel and sequential 'box are good for approximately 6,200 and 4,300 miles respectively before they'll need a rebuild. As for the price, you'll have to ask Arts & Revs, but it won't be cheap.