We tried to install the tpms sensors simply in the spare tire cavity and aired to 33 psi. (No need to drill wheel for valves as the whole sensor is INSIDE the pressurized environment). Appearently the snesors and receivers need to be located at each corner of the vehicle for the RFI signals to be "read" correctly.
Just about every wheel on the market has a different contour to it's shape, so finding one that fits these specifc tpms is all but impossible even with other Lexus wheels.
This is driving me "batty"