GPS device

Does anyone know a reliable device that can switch ON and OFF according to power. Like when you start car, then it switches ON itself and when you stop cars engine, then it powers OFF. Hope this makes sense
I have a TomTom XL now and it only switches OFF when power leaves from the cord.

I am planning to use this device to totally rebuild my cars factory built-in-dash nav system, because for some reason Volvos engineers didnt think that Baltic countrys would like a map too ;) Its 2003 model with RTI and DVD map. My plan is to remove everything else but the lifting mechanism and screen housing, make my own switch and so on.

Most binatone devices turn on and off with power.

Ok thank you.
Do you know what kind of maps it uses and can i use Garmin .img map on it?

The default software is rubbish, but these devices are easily unlocked, iGO primo is a popular choice for these devices.

http://www.navitotal.com/showthread.php?6936-Guide-to-Binatone-devices

I thought i update this post a bit, maybe someone has the same idea ;)
A friend gave me his Garmin Nüvi 1490T sometime ago for testing and i was very surprised when it switched on and off with cigarette lighter power.
Now i have a Nüvi 3760T and it does the same