MediumRare, on a DVDR the data layer is "sandwiched" between two layers of plastic (equal in thickness so the data layer is equidistant to the two surfaces, hence the reason DVDRs can be dual-sided), therefore the top layer is no more vulnerable than the data layer.
Ian, did you do a readability test before and after with the two DVDRs?
MikeTR, if the TY discs are only lasting a short time, why not just buy cheap discs for the car and keep a master on a TY? By the time the disc has degraded it'll have been scratched to the point of being unusable anyway
You know, just any half-decent Ritek/Prodisc/CMC or similar cheapie with a decent top coating. It's what I do.....