Hi there , alot of people seem to think that the climate control unit on the audi a3 8v s3 & rs3 is computer protected and that if you purchase a replacement for your car on ebay. it wont work and is locked by audi and will cost £100's of pounds for them to replace this for you. absolute rubbish, basically remove climate control unit with plastic removal tools so not to damage unit. then unplug the 3 plugs at the back there is a red tab you pull to release each plug of wires. then connect up your replacement unit with the heating buttons which your other unit didnt have as this is an upgrade for heated seats in your car, the configuration needs to change slightly on vcd. plug in and enter central electrics, select long coding and click on box which says seat heating fronts. then press ok, configuration changes and when you start car it will activate the coding and activate your climate control replacement all done and you just need connection loom for seat heating which runs from green seat plugs to climate control unit , plug and play simple as that.