I'm just about to do a 4x4 mk3 fiesta ,I've bought a full running car and basically plan on sitting my shell onto the floor pan of the donor car difference in wheel base is only 18mm . I'm not expecting it to be as easy as it sounds lol but I'm sure I'll work around what ever I come across and this way I get to keep management,brakes,suspension basically everything .donor car cost me £2k and my fiesta owes me nothing so I can't see it costing me the earth but I'm pretty handy at fabrication.