Hmm... the stupidest thing I have done in my car... Well, there's quite a few
I guess the one that hurt the most... Brand new 2010 Chevrolet Cobalt SS turbocharged... within 24 hours, I hit a curb at 45 MPH on the side of the road with the right side of the car. Bent the front rim and the rear hub. Rim = $600 (Forged aluminum), hub = $280, Labor = ~$95 an hour (xx hours). The rear rim had some curb rash, but it wasn't bent or warp. Got it fixed for $50 a few months later. Luckily no body damage (this car had a front lip that is about as low as the BRZ/FR-S).