reply to IPPlanMan
Re: Better off with a removable tablet... Agreed. What happens if you want to change carriers and your in-dash unit isn't compatible with other carriers? What happens when you drive to Mexico or Canada and your chosen US carrier isn't GSM?
The idea of having Internet access in the car and sharing it with multiple passenger devices is neat but building it into the car seems like the wrong implementation.
The auto manufacturers must be taking this route because they smell a recurring revenue stream. Even though they might only get pennies per subscriber per month, if you multiply it by millions of future cars, I'll bet it smells pretty good. Top this off by the fact that the car owner now pays for a connection through which they can spy on your car's computer and "upgrade" it. BINGO! There's plenty of justification!
If we forget recurring revenue, access to the car's computer still seems better if inverted where the car is a WiFi client to whatever is in range.