 Best day was when I got rid of my 2003 Audi A6 after owning if for 3 months.  Second day after I got it I was in the shop for an electrical issue.  In three months I had 2 other electrical issues but the real kicker is that fact that after sitting idle for a few hours the car has a "warm up" period before the car will drive.  Not to mention I get 12-15 MPG around town.  