Is a 98 Audi A4 quattro w/ 70k miles reliable?

I am considering purchasing a 98 Audi A4 w/70k for considerably less the kbb value. My only question is. are they reliable, and will it last me the next 3 years? Besides having a clean record and everything what should I look for? Are there any major defects with this model? Please let me know your thoughts. Thanks for your help.