i havent heard any reports of the dogbone mount under the trans tearing out or wearing out however it is very very soft - like a hard stress ball. i would examine the top left fluid filled mount. for awhile i was mistaking coolant for that (since the 14 turbo coolant overflow tank dump will leave fluid in the same spot). if you have a "coffee stain" there it is the mount losing it's fluid.
what plugs did you put in?
what plugs did you put in?