If i were you I will fight with BMW NA, try other Dealership. make no sense that TPMS can void warranty, how about if some one has Spacers and they take to Dealership for some Warranty work, will that Void the Warrant too ??
2007 335i E90 | Sport pkg | Premium Package | Navigation | Logic 7 sound | Jet Black | Perilli P Zero Nero A/S, 225/40ZR18, 255/35ZR18 | 12F/18R Spacers | Black kidney Grills.
2007 X5 4.8 | Sport pkg | ZPP | ZCW | ZPS | ZTP | 3rd Row Seat | Entertainment pkg | HUD | Jet Black |Continental Extreme DWS.