There is NO PRODUCT that will not "void" the BMW warranty. Period.

As discussed above, Dinan has a supplemental warranty- better than nothing.

Any tuner that says "undetectable" or "will not void the warranty" is a liar. (see note)

It is really astonishingly simple:

Pay to play- assume you might blow up the engine. (People have blown up tuned motors at partial throttle and not "flogging' the car...)

Buy the absolute best tune- which is a total 'bottom up' reprogram of the DDE that allows the computer to accurately respond to actual conditions and parameters- ie no "fooling" sensors. Remap, refuel, etc.

A

Note: When an engine is 'over-clocked' so to speak, the response of the DDE- increased boost, operating parameters- are all stored in the DDE memory. In the BMW TSB about "aftermarket programming" BMW encourages techs to look for evidence. I've heard techs will get bonuses when they find a violator...