You could prank a car with a fish (what you do is tape or wire a fish under the firewall, so in a day or two the car reeks of rotten fish). This might fit in with your ideas number 12 and 14 above.
Functionally, the car object should work like the Travel button on the phone too. Have a "Travel..." menu option along with what ever else you can do with the car. Clicking on "Travel" brings you to the same options as the phone menu.
I think with option 11 - fuel - the way to handle that is to just charge a simoleon cost once you travel. (Realistically, how often do you put fuel in your car at home) ? Perhaps this could be adjusted according to the characteristics of the car and any eco-pack NAPs in place. An older car ought to cost more to run than a newer, more efficient car. Electric cars might have no travel cost, but simply increase your household power usage while they recharge.
