If you’ve ever bought a used car, you’ve probably wondered how the previous owner or owners took care of the machine. For a large portion of the used cars, you can learn a lot about their history, but there’s one thing you probably won’t find anywhere – how often the car went to the car wash.

Sure, you can probably judge by its current condition, though there’s absolutely no guarantee how often the previous owner cleaned the car. However, the condition of any used car won’t be even close to these three luxury limos from the early 2000s.

Carwow filmed three older generations of BMW 7 Series, Mercedes-Benz S-Class, and Lexus LS, all three in horrific condition. We don’t know their exact mechanical state in detail – all three are probably running – as the video focuses on how dirty and disgusting the cars really are on the inside. And the team took a very scientific approach to exploring the interiors.

Starting with the cabin of the S-Class, at first, things didn't look that bad. It was actually quite clean in terms of items left on the seats and in the boot. It was basically the same story with the Lexus and it’s worth mentioning that the spare tyre is not in its usual place as there’s an LPG tank there instead. The BMW – also equipped with an LPG system – was probably the worst when it comes to items in the boot or cabin not related to the car.

But then come the fun bit – or rather, the disgusting bit. A bacteria test was sent to the laboratory and a drug test was made to reveal the filthy truth about the interiors of these luxury vehicles. The drug test came almost completely negative aside from a positive sign for something called Buprenorphine, which is sometimes used as a painkiller on prescription. It was found on the dashboard of the Mercedes, though no one could really tell the history of its appearance there.

A lot more disgusting things were found in all three cars – learn about them in the video – though we have to disappoint you that the cars weren’t treated with a full interior wash and clean by a professional detailer.