I should have bought one of these a long time ago.

I have a Plug-in Prius without a spare tire, and they ship a semi-proprietary
tire goop/inflator combination that kills the TPMS sensor.

I bought a kit with a tube of TPMS-friendly Slime and a 12v inflator. Instead
of going to the gas station, asking them to turn on the air (that used to be
free) and switch back and forth between the air hose and my hand-held pressure
gauge, now I plug the inflator into one of the lighter sockets, attach the
hose to the tire stem, turn it on, use the built-in gauge to check inflation,
and flip the switch when I get to the pressure I want. Repeat x 4.

So. Much. Easier.
--- SBBSecho 2.33-Win32
 * Origin: http://realitycheckbbs.org | tomorrow's retro tech (1:218/700)