Well, any of the oddly-angular armored cars look like they'd be great if you took off the wheel wells and added some boosters...they have a lot of unique angles, but plenty of flat surfaces. Adding some lights, boosters, and small glass bubble cockpit etc. you could get some neat junker type shuttles.

^Dingo

^BA-64

^AEC Mk1

^Another BA-64.
Lots of cool little weird armored cars, that could be excellent starting points. These pictures were all taken from the Mini-Art 1/35th scale...but you get the idea. I thought a trip to the toystore to pick up some cheap airplanes would allow you to slap some wings on them etc.