i cant bring myself to do it as i bought a new tom tom earlier this year which included uk/euro maps for 2 years free. plus if i had a tom tom stolen / snatched from the car not a big deal, but losing an iphone is a lot of cash for me.
if the app is £60 how much will the mount be? id guess £90 ish, for that money you can buy a good dedicated tom tom which you can loan to family/friends and has a resale value at end of life, where as the app you cant sell on, the mount you could of course!