As a first post i thought i would share a bit of advice, i have seen numerous post,s saying about disc read error on the sat-nav and scratched disc,s.
this may have alreadyy been posted somewhere else but here it is anyway!!
it may sound daft or risky but i can assure you it does work every time unless you have a faulty unit
you just have to polish the disc with something slightly abrasive!!
i use solvo chrome cleaner to get rid of deep marks and scratches,
and then finaly finish polishing with meguire's deep crystal polish
dont press on to hard you may crack the disc
and use a micro fibre duster so you dont put anymore scrathes on it!!!
this realy does work and the scratches will disapere
and you cant wipe the data off the disc as it is not on the surface but burnt into the disc
try it what have you got to lose and much cheaper than a disc!!!!!