What about a no-door option? It would be simpler and cheaper to build as well as more rigid.
You mean the ARV6 perhaps Peter?
Yes - that's one thing that gave me the idea (and that car looks really good). Also, with the 3 wheeler, it is quite easy if you are still reasonably mobile to get in and out, especially if you have a steering wheel spacer, so I presume it would be possible for the 4/4 and Plus 4.