I have around 64,000 miles on my 06' 4.8is and I have driven it pretty hard, for the past few months ive been driving back and fourth from NJ to CT and she hasnt let me down (knock on wood) I have never had any major problems, the only thing ive just ran into today was hearing my two front rims are bent while in the process of powder coating them black Luckily, i got the wheel and tire insurance so that should help me. As long as it is certified pre-owned i dont think you have anything to worry about.