They did! Its called a 502x.
If you're talking about the next belt TRF buggy to be produced by Tamiya, well, I dont see one coming anytime soon.
I think Tamiya is going to continue shaft drive development with its buggy designs from here on out; ie. DB02 and TRF512 etc...
Its a shame, if you ask me, because I like belt drive for good reason.
