 I've looked into what can be done to improve the ride comfort of my 2014 Altima. So far, I have not found any recommended suspension improvements.  Really noticeable sitting in the front right seat. I feel road bumps right through the seat and up my spine. The light weight of this car to improve gas mileage, results in too much road bounce on less then smooth road surfaces. Hit a pot hole, and the suspension feels like it bottomed out.  On a smooth road surface, the car is quiet and comfortable. Engine compartment noise, on acceleration is too high.  I've been test riding other cars but the trade in value of my 2014 Altima is less then what I still owe on the car by several thousands of dollars. The appearance external and internal is super. But I would not buy another Nissan Altima.