Yep, we've been mulling it around too. Here in Monterrey the vehicle theft rate has dropped considerably and part of that due to the fact people are installing LoJack and other GPS devices. Almost all major commercial carriers now have satellite tracking. Many cars have been found just because someone left their Iphone in the car at the time of the theft and they are recovered immediately. I think we are sold.
I still like the idea of the sticker on the side and on the back of the rv that says "este vehiculo esta equiapado con rastreo satelital" or "este vehiculo cuenta con equipo GPS".