a while ago i saw this video https://www.youtube.com/watch?v=Q2oevP2eKNk and wanted to get the files, i eventually found and downloaded them
i found them on my computer hard drive after forgetting about it and decided to make it easier for people to find them so i uploaded the files here

if you have a smaller 3d printer you can print "roll cage", "roof" and "shell frame" separately instead of "090 shell" which is all 3 in one

here is an article about it
http://www.hobbymedia.it/41275/bfbuggy-lautomodello-rc-stampato-in-3d

i'm not taking any credit for this creation i'm just sharing something cool
ive found the original creator, David sparling http://www.davidsparling.co.uk/3d.html

the roof file isnt actually the roof, i thought it was when i was splitting the body, it is actually the bonnet and boot

i did a quick estimate for the cost of materials
its about $16 @ $20/kg at 100% infill

user james_III has modified some parts to make them fit better, here is a link http://www.thingiverse.com/thing:692161
here is the build thread http://www.rc-hemmot.com/keskustelu/viewtopic.php?f=4&t=16 you may need to translate it

ive uploaded the original solidworks files in the dune buggy print files zip which david linked in the comments but the link doesnt work anymore, they are in .bfb files, i think they are for the bits for bytes 3d printers, im not sure as i dont use solidworks

i did a quick test and shapeways costs $200-$300 for a set of steel gears maybe coating the gears with copper/aluminium tape would help with wear