Here's an important note about the TomTom carkit:
You can only install the TomTom cradle on your dashboard once, because you need to install an adhesive mounting disk on your dashboard – the one were you'll put the suction cup on.
"Remove and discard the plastic film from the adhesive layer and place the disk on your dashboard."
I personally don't want anything on my cars' windshield and neither on my leather dashboard. I'm so glad to have one built-in by the manufacturer already. Even my todays rental has in car navigation, and I don't think they would accept me placing anything semi-permanently on their dashboard either.
Don't you think that having stuff on your windshield is foolish? I do* but then again that's why I buy Apple gear... because its different and wonderfully designed and engineered.
I also own a Harley and I don't want the cradle anywhere on it. That would just be ridiculous.
Do I like the TomTom application? Yes, I have been testing it a few weeks (Beta tester) and I must say I love it. However, it doesn't compare to a real built-in car navigation set (sorry Ben) – I'll be using it mostly for walking and bicycle routes (just to let other hikers/bikers know it exist).
* I love the special note regarding driving in California and Minnesota and hope that other countries pick this up soon – Germany is probably the first because of an accident there, where a navigation device blocked the drivers road view... missing/overlooking a pedestrian crossing a road.