We just bought a new car , and I'm still riding that new car high. Everything about it is fresh and exciting. There's even still a faint trace of that new car smell, and I'm constantly looking for excuses to take it out for a spin ("Oh look, the milk carton is almost halfway empty—better go to the store to get another one"). Our old car, in contrast, had reached the "I'm annoyed with everything about this piece of junk " phase. Don't get me wrong—there was absolutely nothing wrong with the car,…