When my car 05 G35 (560 miles so far) sits over night or the 12 hours I am at work, I get a vibration in the steering wheel that lasts for maybe 3-5 miles, then it is fine. Until it sits 12+ hours again.

I think it is a flat spot on one of the tires.

When I picked up the car, they had the tires at 47psi. I called the service department who advised they do this to avoid flat spotting when the cars sit on the lot and they must have forgotten to let the extra air out during PDI.

I have since set them to 30psi per the door sticker.

Any ideas?

I figure no sense in taking it to the dealer as it is guaranteed I will get a "unable to duplicate customer concern"

 

I would run the tires a little higher than 30...if it persists and is a problem, it will most likely get worse over time....so, you could just wait until it becomes more frequent and/or for longer durations..then take it in....and at some dealers, there seems to be a little battle to get things done under warranty....thankfully that's not the case at my local service dept...good luck