Hi, I went to view a 2001 Audi A4 130 TDI SE Here is the link: http://www.reallymeansounds.com/motors/index.php?id=11508 I have a few questions I would like to askAudi A4 owners and not the person who is trying to sell me the Audi. 1. The original Audi radio is in the car, is this replacable with an aftermarket radio system because it looks built into the dash. 2. The buttons on the Climate Control unit are all worn, is this normal for Audi's? 3. There is a current problem with the back doors. They will not open from the inside is from the outside, the fella selling the car said it just needs attached to the computer and it's an easy fix, he said around £70 would do it. Has anyone heard of this problem before? I might tell him to get it sorted before I buy it. Also there is a button inside that says ESP, I pressed it and nothing happened. What is it for? Please help!!