Worst experience is that I went to the Ford dealership to see if they had a Boss mustang in the showroom though I really wanted to test drive the 5.0. I parked a little ways away so the Salesman didn't see the Bimmer. I ask him if they had the new Boss he says hell yeah we do it's inside. I'm pumped go inside it's the damn GT500. Walked away and went to another dealership.
Best experienced is when I bought my 135i. I originally wanted the 335i the saleswoman at Pentagon Car Sales (Military program) says I've got a 135i demo car to test drive today. After going over the differences and test drive paperwork, she hands me the keys and says try to be back in under an hour. I'm trying not to smile and I test drove the shit out of that demo by myself. Needless to say I had one on order that day.