Here are a few places to download rns510 firmware, and other tools
Volkswagen RNS 51 Firmware Download Repository | my-gti.com
Tutorial - How to Update RNS-51 Firmware. ***New Links & Firmware*** 19/2/12 - page 1 - Sat Nav and Car Audio - MK5 Golf GTI
Volkswagen RNS 51 Firmware Download Repository | my-gti.com
Tutorial - How to Update RNS-51 Firmware. ***New Links & Firmware*** 19/2/12 - page 1 - Sat Nav and Car Audio - MK5 Golf GTI