any tune WILL void warranty. but as long as they dont find out, they wont know bout it and your warranty will stay intact. if you do have huge engine trouble, and they find something on your ecu that is not according to spec, they will blame your engine troubles on the tune and your warranty will be void.
Current: 2013 F10 M5 & 2013 GLK350
997.1 GT3RS (gone)
2009 WRX STI (gone)
e92 M3 (gone)