Hi,
I use a heads up display in mine that is connected to the OBD, every now and again it screws the gear change and stops it selecting, it has also Made the whole dash light up. I have had to pull over and restart he car to reset it.
I doesn't do any lasting damage and only happen on a few occasions.
It's a something that I did worry about at first but it only seems to happen when I'm starting off and the HUD is calibrating.
I think that the unit uses Canbus but this not 100% implemented to standard in our cars, at least not in 2002 cars, I could be wrong of course.