I have a Hypertech PP+ for my C4. Before I sold the C4, I detuned the car using the Hypertech PP+. I am (nearly) 100% sure it detuned correctly (although anything's possible, i.e. cord getting pulled too soon, PP+ becoming corrupted, etc). After detuning, I pressed the 'START' button to see if it said there was a VIN programmed into it. It did not say anything about a VIN. I then sold the C4. The Hypertech was then sold to a C4 owner. When he received the PP+, it wouldn't tune his car. It kept hanging when he attempted to run the download. He returned it to me, then I checked that his VIN wasn't in it. It wasn't. It didn't say there was any VIN in it. I returned it to Hypertech. They said a VIN was indeed in it. They read me back my old C4's VIN. They said they would send me a new PP+ loaded with my car's VIN. Since I no longer have the car, I can't untune the PP+. So what this boils down to is, is there a way to untune a HPP+ if you no longer have the car? I'm almost 100% sure I detuned it correctly so I am completely miffed on how this happened. I don't feel I am doing anything wrong by untuning it because it is extremely inlikely that the PP+ program is still in my previous C4. Anyone know how to untune it, or should I just toss it in the garbage? Thanks!