4,000 miles on SL. It's juddering when accelerating between 40-50 mph and 1500-2000 rpm. Also when coasting down a hill.

Any advice as I prepare to take it in?

 

i had a symptom like that on a Honda and it turned out to be something with the front suspension and/or transmission. Good thing you're under warranty so let them check it out and fix it before it gets worse.

 

Could be related to the CVT. Mine has it to a lesser extent.

 

I had this issue worked on last December. They rebuilt the valve body to fix the issue. I put 100+ miles per day and am facing a repeat now that I've reached 27,000 miles. Right now it's just annoying, but I fear that could face a breakdown in the future. I'm waiting for a call back to learn what they will do for me. I don't want to be rebuilding the transmission every 12,000 miles.

 

They are about to replace the valve body for my transmission. But I have great concerns long term as well.