I have a 2002 SC430. I found only one non-OEM manufacturer for the 2002-2006 TMPS, Standard Motor Products (the OEM is made by a company called "Pacific"). They were much cheaper, aroud 60 apiece. The sensor numbers are: TPM-61, 62, 63, 64. They are sold for each specific wheel location (such a right rear) just like the OEMs. The are also sold pre-programed so once they are installed, they just need to be registered in the cars CPU. A local shop had software to do this (and it was not a special Toyota or Lexus program). BTW, I noticed that the OEM TPMS sensors were much cheaper at the Canadian delearships (California delearships were about 30% higher).