my experience is that becarefull what hinges you are buying, theres some really bad ones. the material is really full of "bubbles" and the "early castings" breaks relly too easily. especially the lower ones. i would think that hindges made of steel would be better than aluminium, (the door is heavy & long)
thesamba.com has lots of writings and photos of this subject, trust me, i also wrote in there. ;-)
http://www.thesamba.com/vw/forum/viewtopic.php?t=192753&start=0&postdays=0&postorder=asc&highlight=hindgesJyri