I have tried a few different types and have settled on the Doran system.Works well with 6 wheels anywhere on the tow vehicle ( or more ) and 6 on my caravan when required. (Booster used gave better pick up of spares on rear of van) has a neat Drop and Hook feature for trailers.
Reciever sticks on screen with a sucker thing.
External sensors read pressures and give audio and visual warning when pressure drops. Sensors can be locked quite easily to prevent theft.
I tried a system with internal sensors but it was a lot of work IMHO.
They have a dealer now in Perth I gather.
http://www.doranmfg.com/tirepressuremonitorproducts.htm

