Difference between a tune and a piggy back. And is there any warranty that would allo

[Matt Fojtik]

I'm about to buy an e92 m3. But, I need to get it with a warranty and thus I can't really tune it. If I put a piggyback on is it untraceable, so they can't tell I messed with it so I can not void it?
I know dinan makes something like this but do you guys know of anything else?
I'm wondering because I would like to tune for the benefits and also I plan to put on test pipes so it would be needed.
Or is there any warranty companies you guys know of that would allow a tune like alpine mss?

Thanks,
Matt