How to make a protoype shell?

[BenG]

Ok.

I have on the quiet finally finished my *first* prototype B4 conversion. I still have many mods to make, however, I want to make a shell for it now, as everyone else does, like out of coke bottles?

Please help.

Also, can you tell me the best materials to use to make a mould?

I was thinking car body filler.

Thanks,

Ben