You know your oil filter was on too tight when you can't get it off with the wrench, so you stab it with a thick screwdriver to get some grimp, and damn-near tear it in half when trying to turn it.
To buy myself some time with the rear mount, I cut up an old rubber mousepad and stuffed it in the gaps. I plan to replace it in the not-so-distant future, but this'll lessen the strain on the other mounts.