http://www-nrd.nhtsa.dot.gov/vrtc/ca/tpms.htm
http://www.tirerack.com/accessories/.../smartire2.jsp
$229. Just need to find an installer.
UPDATE (more links):
http://www.vulcantire.com/smartire_pass_sys.htm
$199. Same one as above, but $30 cheaper!
And, their full function displays are $45. They show you exact pressure and temp of each tire. And for you hypermilers, they sense pressures up to 78 psi! Anybody interested in a group buy?
UPDATE: I talked to someone at Vulcantire. We'd need at least 5 units in order to get a 10% discount.
http://www.mypatienteducation.com/wirtirmonsys.html
$284.95
https://www.shop.pressureproca.com/d...1&categoryId=2
$375