Billybobajob

When should toothed belt be changed on a 13 plate A4 Avant please? Also front discs have 3 obvious score rings, despite new pads. Should discs be changed? Rear windscreen has internal scuff marks that will not polish out. Heating elements a work fine. I'm told these marks will show through if screen tinted. Any suggestions please?

Looking forward to enjoying my Audi with help and advice from Forum Members