My wife-to-be hasn't killed any yet but she sure tries hard to. At least she knows to change the oil and pays attention to the tune of the car- unfornately. The only thing shes managed to do so far is to break the welds of the exhaust on two of the cars. I really don't know what's she's did to my festiva, been awful cranky lately. Although I've noticed if I pop open the hood at least once week on the cars she drives or has driven the drives seem a bit more pleasant
. A side note though all the cars run a little better after she drives them for a week. So in my opinion a little WOT doesn't hurt.