Are you referring to the split rim OZ racing wheels? I do not think they are available as separate rim/tyre sets. To be honest, they are quite small and would look a little odd on a Tamiya kit. Personally, I think you would be better off using the rally rims from the Evo 5 and sourcing a set of road tyres (i.e. from Aoshima's wheel and tyre sets). If you are dead set on the Hasegawa rims, then the only way you can get hold of them without buying the kit is to contact Hobby Link Japan's parts department via email and they can order them for you:
[email protected]