When parking towards curbs, I use my side mirrors as a reference. I line up the bottom of the side mirror with the curb and I end up pretty close to the curb, but never hitting it. Depending on your seating arrangement, you can try this next time!
Current: Alpine White F10 M5|H&R springs|12mm/10mm spacers|Eisenmann Race
Sold:Imola Yellow RS4-KW V3|MTM 10mm spacers|Hotchkis rear sway bar|APR Stage 1|Milltek Catless|RNS-E|Euro RS4 Flat bottom Steering Wheel