sounds like you might want to call your service center,and based on the cars you own,you should have a good relationship with a shop close by.....is engine running rough??? Engine misfire will cause roughness but would must likely turn on service light.....broken/grounded tranmission/engine/exhaust mount would give similiar feeling. Without seeing condition first hand in person it would be very hard to give correct diagnosis.
Many thanks for your reply. Its really getting to me and kind of bumming me out. Engine isn't running rough at all, purring like a kitten. I went out for a long drive today and all was great, even stopping and moving again from red lights and traffic, all was fine, only when I came home and was pulling into my garage car started vibrating and jittering violently from the rear end. Making a similar sound as though you are carrying a silver tray with metal objects on it and you're shaking the tray. Kinda seems like the exhaust may be loose and vibrating violently (but I don't understand how that could have happened). As a result whole car started vibrating. I switched it off for a while, and then on again and tried to reverse, same problem so I put it back and left it there. I texted a bunch of the guys I know who work at the dealership but no-one has gotten back to me yet.
Unfort I guess I have no choice but to put her on a flat-bed tomorrow and go to the dealer. I really hope this isn't a software issue the dealer has to reflash my ECU or somehting and I end up losing my CA Auto remap! I also don't have any warning lights or anything. I hit the button for a system check and it gave me the OK.
I don't know if it could be caused by my filling up with gas today maybe the fuel was lower grade than normal -- no clue. Maybe also on my way home I passed by a small tunnel and I downshifted like 2 gears for a nice big rev and it hit redline around 8,000rpm-ish (didn't mean to do that) for half a second until I moved back up in gears -- maybe that could have done something.
I'm obsessing I know -- but all my forum and google searches have given me zero results. And although I like to drive hard at times, I never abuse the car. Have owned her since Jan '09 (so warranty still valid!) and yet have not once, ever, done a launch control. I've also recently changed my tires, but new PS2s on the car and have never tracked the car.
So I'm confused, and definitely think its time for a beer.