GM has gone one further, the TPMS sensor on some of the new ones is in fact a rubber valve stem screwed on internally to a sensor. We replaced 2 sets before the service manager conviscated the side cutters at the tire machine and made the techs remove the valve cores prior to changing tires. The techs used to use the side cutters and cut the stem off, which usually broke the sensor if it had TPMS and didn't realize it. We treat every Ford coming in as if it had it, because of the strap type ones they use. The local Nissan dealer refuses to service the sensors, we had to swallow a couple of hefty bills from them as a result. GM had the best set-up as far as I'm concerned, they used an indirect TPMS run off the ABS system, it's not as accurate but created no extra serivicing headaches.