Thanks for your comments guys, .... in answer ....
I think the tomtom software is great, the 3D view is really easy to use and the voice prompts are great. However I have not used or even seen any other GPS software to compaire!
Not sure about the M6 toll-road, currently I have traveled to and from work in Derby

but am going to Cornwall on Fri
I searched for comments on magnetic damage on the PC or Lith battery and everyone seemed fine with it. It has a small plate that you stick to the back of the PC (Or some stick it under the batt cover)
Thanks for the idea MarkW19 :d .... it was you that gave me the product link :d
harvey, your setup sounds good, I think I might mount the GPS UNDER the rear parcel mash, It still gets a good signal and I could run a wire to the cubby hole. However my Cooper S didn't come with a rear cigerette socket only a blanking plate
I'll tap into power when....
1. I know what wire to tap into in the cubby hole ... and
2. When I find a car charger for the GPS unit that doesn't come with a holder
(I do have a 'bulky' 12v to 240v power converter for emergencies while i'm away from the home

)