Improving in-car infotainment has been one of the focuses between car companies and other tech companies. They range from being able to track the location wherever you are, providing directions to allowing you to access Facebook on the go.
The lifecycle of cars is much longer than the lifecycle for consumer electronics. I see two opportunities. First, the time is ripe for some cost effective electronics entertainment retrofits to cars. My 6 year old hybrid doesn't even have an audio jack for my smartphone. While planning ahead for the technologies of the future is nice, I'd guess that cost effective upgrades for USB and smartphone connectivity could be a rewarding market. Secondly, a 120 volt emergency power inverter retrofit package for cars could probably do very well if the power failures over the past two months in New England are any indicator. The cigarette lighter outlet nowhere near taps the power potential of a vehicle for emergency use.