2002 VW GTI Radio Question

My girlfriend has a 2002 VW GTI, for which she has installed an after market radio and threw out the original (years ago). Every time she brings it into the dealership for service, they tell her that they have to remove her new radio and install a VW radio to access the computer. The weird thing is that she does not have to do this when she brings it to a random gas station for an inspection (which I believe also requires them to check the cars computer).

A) does this make sense or are the dealers full of it.

B) She’s thinking of buying another new radio for it, one with an AUX port, and if she did so, would want to get one that would allow the VW dealership to access the computer without removing the radio each time. Is that possible?

The dealer’s diagnostic tool has the ability to access many different computers in the car (engine, abs, airbag, etc.). The original factory radio has an internal computer that can also be accessed by their diagnostic tool.
The problem is that if an aftermarket radio was not wired correctly, it has the potential to short circuit the dealer’s scan tool leaving them with a very expensive paperweight.
As a precaution, many dealers will not scan any car that has an aftermarket radio.
That being said, simply removing the radio should be sufficient. There really isn’t a need to install a genuine VW radio to scan the car.
My experience has been that simply turning the radio off (or pulling the fuse) works fine. But, the scan tool I have for VWs has built-in protection to prevent it from getting fired in these situations, so I’m not overly cautious.
If you showed up at the dealer without a radio installed, they might scan the car without any hesitation.
Check this out for more info: