The FR500 are not a knock off of the Ford GT wheels, especially since the FR500 concept was done in 1999, way before the Ford GT projects was first started.
There are Ford GT replica wheels and they are sick.
is the manufacturer and they sell them direct and sometimes on ebay.
I had FR500 on my old 98 GT and I liked them but wish I would have gotten chrome instead of black. I would buy the CTR wheels if I had it to do over.
Here is a pic of the FR500 on my old car.