One tiny little transmission cooler hose on a F#$%@&^% Audi A6 twin turbo... Whole front of the damn car had to come off.
944 Turbo clutch.... Miserable job
Multiple week long rush repair sessions of BAD wreck damage on dirt track race car.... Often finishing on the following Saturday afternoon right before leaving to race again when hovering at the top of the season point standings.
Since I bought my first cheap POS car in about 1981, I have always done ALL of my auto repair work (other than tire mounting and balancing). Partly because I was (and still am) cheap, partly because someone told me I couldn't and in later years because I don't trust anyone else to do it. I have had more than my share of tough repair jobs and thankfully for my sanity, I have mostly forgotten many of them.
