I must be missing something. I have run VW's for nearly 18 years, a Rabbit in ITB, a MKII GTI in ITB and now a MKIII Jetta in ITB, and even a Golf in the VW Cup. I have never broken an engine mount utilizing stock mounts. On the MKII's we found out from the VW Cup that the rear mount on the drivers side was weak, so one trick was to put a piece of chain between the flange where the mount attached to the chassis cross beam and the mounting bolt from transaxle, of course longer bolts were needed.On the front mount of the MRII, we stayed with the earlier style.... But on the MKIII we have never broken a mount. Use a stay rod on the front....(Like Dr. K) on the lower side. But still use stock parts for the rear engine mounts. You don't suppose that the root cause of the breakage is from something else?. Welded diff's, driving style, etc..... What other parts are failing or have limited life?. ... Just a thought. Race and have fun....
David Ellis-Brown