Yeah, check the motor mounts. Mine did the same thing on shut down before replacing. Actually I was getting vibration in neutral that would go away when in gear. New motor mounts and life was much better. I've never checked my transmission mounts, do those go bad?

I can't say that my car upshifts hard. Could be a vacuum problem as others mentioned.

Check your fuel lines for air bubbles. Mine had that problem...and got worse over time. Car was not happy when started cold but would get better once warmed up. My guess is that the o-rings expanded just enough from the heat to stop the air leaks. But as the o-rings/fuel lines got worse so did the problem. Replaced those parts (common on these cars) and life was much better, again.

I've never been to Cleveland, so I can't tell advise you on the weight motor oil you should use. In Maryland in run regular oil (gasp!) from Jiffy Lube (gasp!).

Chuck