Quick "Travel" detail kit. (for emergenices).

[OneEyeJack]

You could try a can of Pledge Furniture Polish and a rag. It will get spots off and leave a good shine with no traces of wax or polish behind. It works great for touch ups. It's good on the battery and in the engine compartment, too.

 

[Unicorn01]

I just carry a bottle of a quick detailer to remove bird droppings, and window cleaner. Along with a few rags and paper towels.