I was curious so I found GMP's website. GMP Diecast. More colors, and better photos. More expensive too. That guy must have bought a bunch to get such a low price. They look to be done very well, and they didn't miss many details. But they do have last year's LS1 in them.
This is a friend of mine who has become a GMP dealer. If you are interested in any of the other colors gmp makes he can get them also. Let me know if anyone is interested and I will get you in touch. Again the detail is much better than the other diecast cars.