Mileage adjustment - Z4

[john_p]

Further to this
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

I'm curious to know whether it's a trivial task or not to adjust the mileage on a Z4. If it's not, how is it possible for the mileage to go down??

edit: if it is possible, are there any flags triggered that can be found by a dealer, or does it require written permission from BMW etc

little worried that "guy with a laptop" has reprogrammed it, but no idea if that's feasible or not.

Edited by john_p on Monday 21st January 20:06