I found them at Walmart and others found them at Joann's Fabric's...Make sure you get the correct sizes. Front wheels are 1"1/8" and the Rears are 1"1/2" the fit in there perfectly, but did find on some wheels off other cars they were just a hair off, but they will fit, no glue is even needed they fit nice and snug.. I think I paid 2.86 for the large ones and 1.96 for the smaller ones Good Luck and thought I just share what I found.
Bobby