I recently bought a '13 G37x with 33000 miles from a private seller. I am noticing a problem with my driver's seat. Whenever I accelerate hard r brake hard, I feel a movement in the driver's seat bottom (front and backward). The movement is not much (about 1 mm). I narrowed it down to the movement in the seat rails. Dealership checked it and says its fine and were not able to replicate. My fiancee also cannot replicate it (I am 240 lbs and she is considerably lighter than me, so was the service tech who checked my car). Has anyone else experienced this issue? This is really annoying every time I brake or accelerate and taking away the driving pleasure.
My car is out of warranty

 

Check the rails, there’s a lot of play in them in the G35 and it’s a common problem. One of the rails is going bad...

 

Its the right side rails that have the play. I am wondering if there is any DIY solution for it.