It would be very intesting to see if there would be another Batmobile, or any other mode of transportation. I think he should just get himself another tumbler and modify it even more. He shouldn't be using more military prototypes anymore because that's how he almost got exposed in the first place. Imagine if he had a prototype airplane he uses as a batplane! By then his employees would put two and two together. But this is a discussion on the Batmobile. Yeah, like I said, use another tumbler, and modify it, make it so it looks less and less like the original prototype, and make it more Batman-ish.