This is the story of why one of the most dominant race cars of the modern era, the IMSA GTO Audi 90 Quattro, had a little doll that mooned other racers.

Back in 1989, these Audis were so dominant that one non-Audi competitor made up a “no passing” sticker with Audi driver Hans-Joachim Stuck’s face on it. Hans-Joachim Stuck had the best response ever: moon ‘em when you pass. Stuck’s GTO-class Audi 90 quattro featured a doll in the rear window who’d drop his trousers whenever Stuck flew past.

It’s a good thing we light-hearted Americans allowed such frivolities. And by frivolities, I mean butts.

The full video on Audi’s American efforts in 1988 and 1989 is a delightful blast from the past that’s worth watching in its entirety, too. Audi’s all-wheel-drive 200 Quattro so thoroughly dominated Trans-Am in 1988 that Trans-Am banned both all-wheel-drive and non-American engines the following year.

So, Audi moved to IMSA’s GTO class for 1989 with a tube-frame Audi 90 Quattro that was just as bonkers.