Needed 4 new TPS (tire pressure sensors) so i did some online research and came across this site http://www.tire-sensors.com/. The sensors are on sale as of now from $35 to $32 a piece. Not a bad deal considering that they normally sell for well over 50 dollars each, new from the dealer. They give you a 12 month guarantee and the Li-Ion battery lasts for ~5-7 years. Any thoughts?