To me, using navigation on the phone would be more of a convenience than a matter of savings. The 99 euro GPS I was talking about was the cheapest in store and

To me, using navigation on the phone would be more of a convenience than a matter of savings. The 99 euro GPS I was talking about was the cheapest in store and it even had Traffic Message Channel (TMC), something the older one didn't. Also, the GPS would get super hot in the windshield -- I would have never used my phone instead! Anyhow, all that out of the way, I guess you are right that turn by turn would be nice on iOS.