After doing some searching, I found a valuable .PDF document which provides the Continental Tire (VDO) part number for the Tire Pressure Monitor Sensor used in the Model S after VIN 56000... Here is the link to the document ->http://www.vdo.com/media/182593/2015-10_applikationen_tpms_en.pdf These sensors are available from your Tesla Service Center IF you have a Tesla VIN number.
The new sensors are $50/ea from Tesla. Labor for installation and a tire swap came to $52.50 for me. - - - Updated - - - The new sensors are $50/ea from Tesla. Labor for installation and a tire swap came to $52.50 for me.