Trans and motor are one of the few thing's I haven't had a problem with. 30K on mine, including some light towing and both are working fine.

 

"I" mode does allow shifting into 4th gear. It just changes the shift point to a higher speed.

 

I've done 90 in "I" for 3 miles and it never went to 4th. Clicked up and it shifted.

 

Just rolled 62K on mine and use "I" gear everyday and drive my car like I just stole it and have had zero problems. Did have an isssue with the cruise not working after you exceed 110 MPH. According to the dealer, thats a safety feature and resets after you come to a stop and shift into park. Other than that no problems or issues.

 

Different model, different programming. My car usually shifts into 4th gear after I let off the gas after 65 MPH, otherwise it won't shift into 4th if I'm still accelerating.