If our cars could talk, what would they say? I think if mine had a voice, it would scream "NO! NOT YOU! NOT YOOUUUUU!" whenever I walked up to it with a box of tools.
See, like most of you, I love to wrench on my own car. The problem is, I'm not very good at, usually due to a combination of incompetence and a willingness to half-ass the job.
I once tried to replace a burned-out turn signal bulb and ended up cutting my hand pretty badly trying to remove the housing. I actually got blood all over the headlight bulb, which started smoking when I turned it on. (You know, because of the blood.) At least I've never destroyed a transmission or something.
So what's your biggest self-repair fail?