What do you expect to have happen? It takes more than swapping out the CPU chip for an "automotive grade" version to make something be actually reliable in an automotive environment, and for most likely purposes, it shouldn't need to be... I wouldn't recommend replacing your Toyota's brake controller with a hardened arduino, even if the original version does have a bug or two...
(If you're operating in the passenger compartment of an auto, not actually controlling any important functions of the car, you shouldn't need more than an automotive-aware power supply, and a lot of people trust their cell phones and iPods to less than that...)