After-market wheels

[Charlie1]

My wife and I bought a 2010 XC60 last August. We live in Minnesota so in November I replaced Pirellli Scorpions, a speed-rated tire with low traction ratings, with Bridgestone Blizzak winter tires. Now I want to re-mount the Pirellis on a custom wheel (18-inch). I know I probably need to buy the TPMS valves (tire pressure monitoring system), too. Anybody out there bought custom wheels? Did you use the TPMS valves? Did the dealer give you any grief? (Volvo.com tech support told me that if non-original wheels caused any damage to systems that the warranty would not cover repairs.) The local tire stores scoff...they mount customer wheels on new cars every day, they say. Let me know. Love this car, BTW. Thanks