There is plenty of leeway in that for dealers to use their good judgement.

Or to wriggle out of any claims

it works by saving your complete standard data onto the module' date=' and the performance one.

The unit up loads either, as it flashes with the totally orginal data the unit reads from the car in the first place there is no trace of it been done.

The unit does not just toggle between the two chip files which are stored on the ECU.[/quote']I understand that. But if the ECU is interrogated by the dealer, won't there be engine parameter readings there - eg max boost achieved or whatever - which would point clearly to the car/chip having been modded?

the unit wipes all the modified data and re-loads the standard data it downloaded in the first place from your car.