It shouldn't be too hard to incorporate a bat "face" into the front of the car. And while I wouldn't go with the overdone wing on the roof it shouldn't be too hard to integrate wings into the design. It would be distinctive without being ridiculous.
Although I'm primarily thinking of appearance now I could see incorporating hidden things that could be useful, similar to previous gadgets we've seen on the Batmobile as well as Bond's Aston Martion. A bullet-proof shield that rises at the back. Did they have bullet-proof glass in the '40s? Well, it's Batman so I suppose he could have it even if it didn't actually exist yet.