[Bosch]

Insert is a pressure fit and a washer that holds it all together, when its all bolted together it can't slip out. If you can wiggle your mount by hand without much pressure to do it, while its bolted in the car I would look for a new mount. My ugly mount was still intact, everything still attached like it should be, just a bit deformed from the un-matched upper. If the rubber is no longer attached yeah its time for new OEM piece or a filled piece.

But if you can just basically touch it and it moves - not a good sign.

schucks/kragen auto has a stout OEM replacement mount, it actually has more rubber than the OEM mounts do, that if you wanted to put inserts in you would have to cut away some of the rubber not just the overwebbing to get the insert in there.