One thing that I have yet to find is a good solid car stereo solution. My problem was always that you have to turn the MP3 player one and off every time you get in or out of the car. Then if you forget to turn it off you have a dead battery in your player. There are some solutions but they require you to hack a bunch of mounting brackets and adapters together creating a window display for thieves.
This looks like the solution. A simple USB and SD slot in a DIN sized head unit. While it is just a first step, it looks like navigation and display could be improved. Until then I will be using my trusty old cassette adapter to my numerous devices.
[Dr Gadget via Engadget]