Have carried 4x8 sheets in a transit, they only just fitted, lying flat. So I doubt think youll put 8x4 in anything smaller. The tranny is that size for a good reason.
Estate car will do if youre willing to put them on the roof. If you carry PB you'll need to sandwich it with 18mm chip underneath and 12mm chip on top. Roofracks are nice, but not necessary for light loads, as long as you understand how to secure it properly. Dont do that if you dont though.
You'd be surprised what you can carry on a bicycle... but no, not an
8x4 :)
NT