My name is Bob, I own 2003 grand prix limited edition (3.8 supercharged) with about 100k miles. I took my car to the dealer last week for diagnostic (car was leaking coolant). They told me I needed intake gasket (estimated $1,200). I decided to take it to a friend of a friend that works out of his garage (to save money). This guy replaced intake gaskets but now my car is leaking like a sieve from the heads (coolant and oil). He claims that he did the job right but my heads are warped from over heating and that is causing the leak. I think this mechanic screwed up the job (i base this on the fact that he is a serious alcoholic and was wasted when I went to pick up the car). I plan on having my towed to a qualified shop... what could this guy of screwed up? How much could this potentially cost me? Thanks for your input. I appreciate it.