I've found only 4 manufacturers of high detail, 2 of not-so-great.
Auto-Art is currently by far the best but has only offered the limited yellow & red colors plus the 2 Granturismos race cars (fantasy race cars) in white/black stripes & the other in faux carbon fibre:
http://cgi.ebay.com/AutoArt-Ford-GT...ryZ45349QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Close behind in detail are the Mini-champs in multiple colors (1:43):
http://cgi.ebay.com/Minichamps-1-43...ryZ14736QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
plus the Kyosho Mini-Z r/c products - u can buy the Kyosho base package in black / silver or yellow / black stripes:
http://cgi.ebay.com/KYOSHO-MINI-Z-R...ryZ49213QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
& they offer Kyosho bodies in other colors:
http://cgi.ebay.com/NIB-Kyosho-MINI...eZWD1VQQtrksidZp1638.m118.l1247QQcmdZViewItem
Also, for REAL fun, if u've got the space, go buy a monster Ninco slot car track & a fleet of Scalextric 40's - their GT is awesome (again smaller in size but not like the old Tyco stuff of the '70's), working headlights & faaasst! These display well:
http://cgi.ebay.com/Scalextric-Ford...eZWD1VQQtrksidZp1638.m118.l1247QQcmdZViewItem
Although the Scalextric GT's are getting harder to find based on color - most production ended.
The 1:12 Motormax is based on the concept car & not very good detail, the Hotwheels is the smaller Motormax 1:18 rebadged as Hotwheels so same thing, concept car w/ low detail.
My money's on Auto-Art producing more colors.:thumbsup
BUT the Kyosho Mini-Z & Scalextric slots are by far staright fun fun fun!:rofl
Finally as far as GT-40's go, the 1:12 GMP was the best - if u can find 'em - my #6 cost me $499. I think they still have a few left in the famous gold / pink etc.... also made road cars:
http://www.gmpdiecast.com/products/details.cfm?ProductNumber=G1201317&category=1:12 Scale GT40
Also for GT-40's again, Scalextric makes awesome slots in alot of the variations including the Comstock CAN car if I remember plus a 3 pack from Goodwood a few yrs ago that had realistic weathering in a display box showing the 1-2-3 finish:
http://cgi.ebay.com/Scalextric-Spor...oryZ4781QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Whew, great, now my fingers are bleeding, wouldn't ya know my longest post so far is about toys... lol!
-Rod