Mistake #1: Not keeping Old Betsy running until she has 180,000 miles on her.
Mistake #2: Not buying a used car.
Mistake #3: Not saving a serious down payment while driving Old Betsy to the ground.
Only thing I disagree with is Mistake #2. When you buy used, you buy the previous owners problems. I prefer to buy new. Otherwise Mistake #1, and Mistake #3 are spot-on.