Tyre pressure monitoring
 

not something I 'need' but I love gadgets

anyone fitted one of these tyres pressure monitors?

Buy Porsche Boxster (986 / 987 / 981) Boxster S 986 3.2L 1999-02 Tyre Pressure Monitor | Design 911


as I understand it the sensors must be fitted on the wheel, before tyre fitted.

Thought this might be a good time to fit as I am going to get the wheels refurbished!

I had this (I mean exactly this model) on my Boxster before I sold it. It works fine and does all the things advertised and is very reliable.
I bought mine at TireRack for about $200
Yes, the pressure-sensing stems need to be installed when the rubber if off the rims.
I think it's more than a gadget: I caught a nail in my rear tire once which led to very slow deflation of the tire. The TPMS warned me just in time.
So that alone was worth the investment.

Yup, Orange Electronics TPMS, I've had it on my '06 for around 2 years, and it works great so far. It reads 1 Psi higher than my gauge, but it's always the same 1 Psi.
Orange Electronic Passenger Vehicle Retrofit TPMS System for Sale Online - Vulcan Tire Sales