This article breaks it down a little better. http://www.redbend.com/data/upl/whitepapers/red_bend_update_car_ecu.pdf http://www.redbend.com/data/upl/whitepaper

This article breaks it down a little better. http://www.redbend.com/data/upl/whitepapers/red_bend_update_car_ecu.pdf http://www.redbend.com/data/upl/whitepapers/red_bend_update_... The biggest chunk is obviously the radio/nav system.