Engine shudder in 08 LTZ w/ 3.6

Hey I wanted to bump this post as I am having the same shudder issues. Mine is an 09 with 3.6l and 8k miles. The vibration is noticeably worse when the Defrost is on, but does exist with it off as well. The Main times I notice it is when coming into a parking spot or slowing while turning the steering wheel. It is almost bad enough to rattle the dash. Took it to the dealer and they tell me its normal. Well I cant imagine this being just normal. Also I noticed a shudder while driving around 60 and downshifting to around 3k rpms and giving it slight acceleration. It almost feels like a wheel out of balance but goes away when it upshifts into a higher gear.

The First time I took it in they made me take a ride with one of the service techs. I showed him all the different times it would clunk form applying the accelerator and when it would vibrate the worst. He then goes to tell me that the vibrations aren't bad and its most likely normal. Couple days later I took it back and almost annoyed they said they would look at it. Almost got into a fight with the tech about updating the firmware. All they told me was that they checked the motor mounts and updated the firmware for the transmission. They got this all done in an amazing 15 min. Oh and that the car wasn't throwing any codes so there cant be anything wrong.

Thats about as detailed as it got with the dealer. I am a mechanic and have been for years. But for some reason I cant imagine a car that is nearly new having so many "Normal" problems (quirks)