We have an 06 S with automatic trans that is not fully engaging when shifting from 3rd to 4th when in D. It will "flare" from 3rd to 4th and not engage. The problem can be overcome most times by switching to manual mode. I have been using the paddle shifter on the wheel and most times that works but the longer you drive the car, the higher the probability this technique will also fail. I can upshift to 5th and then back down to 4th which usually works to engage 4th.

Thinking it may be the selenoid for 4th gear, but not positive. Has anyone else besides a member named Noahl had this problem and what was the solution. Dealers just want to pop in a new tranny. No surprise there.........