the magnum has a single piece chassis and thats about it really for the differences iirc, besides the .18. i doubt u will find one in the UK in the near future tho, besides - a 2 piece chassis (as on the funfactor) allows u to swap the front skid plate, and due to the shape of the 2 piece, its probably stiffer than the magnums... but dont quote me on that, im presuming both are the same material...? if u want an .18 in it, get the OS18CVR-X - thought id get that in before anyone else!

Oh - B&Q plumbing section for the 10mm compression fittings for the diff cup mod - only a couple of quid to do the whole truck - scuff the cups with emery cloth and super glue the fittings on, works for me.