Am looking to buy an A4 Cabriolet, more than likely an S4 (B7), I would be grateful on any hints/tips and advice! Would I be better sticking to a lower mileage (34k) or would I be ok buying one with higher miles (60k) and saving myself 3.5k, both the same age. Black or grey??

2007 AUDI S4 S4 QUATTRO 2DR TIP AUTOMATIC WITH TV & SAT/NAV

2007 AUDI S4 S4 QUATTRO 2DR TIP AUTO FULLY LOADED WITH SAT NAV

2007 Audi S4 Cabriolet 4163 cc 4.2 quattro

ANY ADVICE HELP OR CONSTRUCTIVE CRTISICMS ON DO & DONTS IS APPRECIATED.
THANKS IN ADVANCE GUYS & GIRLS