The Tach seems pretty steady... definately not the engine.

I noticed when I tried to take it out for a drive after being parked for 2 months, the vibration was so severe it was nearly undrivable, then after about 5-10 minutes of driving is subsides...

The problem is when I drive it to the dealer, the issue is gone (of course) because I had to drive it there! Now they are telling me they want to charge me if they don't find anything on the next visit... Well the damn thing has to sit in order to replicate it!

Damn I hate dealing with these dealers...