2. Tobacco spit cup
Just...no. Filling an entire cup with your dark brown, tar-laden saliva is disgusting in baseball stadiums, it’s disgusting at home, and it’s indescribably gross in an automobile. When the inevitable happens—it’s sitting in an open-topped cup after all—you’re going to be spending an entire weekend figuring out how to salvage your car. Here’s a hint: new carpet’s only a few hundred bucks for most cars.
1. Any. Bodily. Fluid.
This really should go without saying. Blood tells people you’re a murderer who likely has bodies in the trunk at this very moment. Urine and vomit means you simply didn’t pull over when you knew you really needed to, and if you happen to have intestinal discomfort, for the love of god/whoever else will have to sit in the car from now to eternity, just don’t get in the car.
Aaron Miller is the Rides editor for Supercompressor, and can be found on Twitter. He once agreed to clean a friend's car. After removing the seats and spending an entire day just on the inside, he realized he didn't charge nearly enough.