I have seen a similar topic to this a few years ago but it didn't really help me out.
I have an Audi TT (2001) and have I just used VAG Tacho 2.5 to reset the mileage. But now it reads 999999. Even after driving it the mileage stays at the same.
I believe I need to talk to a specialist dashboard company to help me with this issue. Im from Derbyshire if anyone is local?