I also wanted to get die-cast at first. But it's super expensive
if I go buy those very detailed ones. So I decided to make one
myself. More fun I reckoned. But then I realised it's really hard
to spray the paint nicely on the surface. 
very detailed ones would be from the CMC brand but so far in my
merc collection, i've got one from ebay overseas (silver vision
SLR) & one from Maisto (black colour SLR McLaren)..
very tempted to get the 1/12 scale one though..