i have installed two within the last 2 months. one in the red and other in silver. bought two different systems. orange p409s and the other is P420A, both systems were under 200.00 each. i had to buy a 90 degree tpms adapter for the volks wheels. the stock wheels didn't require the adapter.
I have not found a final mounting spot just yet but if you pull out the ash tray, it'll fit in the space nicely, just need to secure it. wiring is via micro usb to the unit then plugged into the ash tray. I'll eventually hard wire them. The reason i bought the units; i drove without realizing i had a flat, a person on the highway next to me honked and pointed at my tire.
so far i love the system, it monitors the following: tire psi at each wheel, temp (celsius or fahrenheit) and also alt voltage.
system gives me peace of mind, i recommend the kit. I'm sure there are less costly and more expensive kits out there but this kit works for me.
those in dfw, I'm on the side of 114, scary!!!! I wanted to pull off but there was no way
tpms and adapter below for those that might need the adapter
tpms monitor below, forgot which model this is, think its the p409s, both kits seem to be similar, different monitor but provides same readings. one kit came with a windshield mount.
i can post more pictures if needed.... i hope this helps.