I've noticed this ever since I bought the car a couple months ago. On cold starts only I feel a lot of vibrations in the cabin. Goes away once warmed up. I assume it's my motor mounts but anything else it could possibly be?

 

That's the ECU compensating for the lack of heat in the motor thereby causing a rough idle until the car warms up a little. It just runs the motor lean during the startup.

Once the rough idle ends its typically fine for you to drive away slowly until the transmission and engine fluids achieve operating temperature.

 

just the way it is. It's part of the low emissions rating, i believe it helps warm up the catalytic converter faster.

 

What EZ said too.

 

this is a tad excessive. ive driven a bunch of TL's at my work and none are this rough. as much as I like a good butt massage. ill start with the motor mounts and see where that gets me

 

I get some small vibrations when the car is warming up in the morning as well. I just let it warm up for 2 - 3 minutes and it's back to normal. I've always let my vehicles warm up for a few minutes in the winter months before driving them.. just a habit of nature for me.

 

Mine is also this way. Smooth as can be after warming up.

 

Driven TL's at work doesn't change much. Were they as cold? Was the ambient temperature as low? And were they sitting for 12 hours?

Vibrations won't change if any of your mounts have a problem. You would feel it consistently.

Plus your car is a couple months old. There's no way you would have broken a motor mount this fast.

Check on it if you like, its always good know where all these parts are and keeping a look out for them. After all the miles I've put on the original motor mounts I'm impressed nothing's come apart so far.

So I doubt you would have a broken one right now given the fact that its smooth once it heats up.