I'm not sure of the aspects of that class, are there any limits as to what you have to work with?
how useful does it have to be? I'm working on a project right now that involves 62 led's mounted in my roof. (check out page 2 of the link in my signiture.) So if it doesnt have to be all that useful, I suggest involving some led's.
I have a couple more ideas, I havn't really looked into the practicallity of implementing them. I was thinking about some sort of digital climate control (my A/C is broken, so in my case it would just work for heat). you just set the temp. then a microcontroller would adjust the heat coming out of the vents. maybe have 1 thermostat measure the air coming directly from the vents, and another somewhere else in the car.
I know I had a couple more, but I'm kinda burnt out from a long day at school.