Very common ailment of the G35, I was shot a price of $985 plus $68 labor, laughed, went to Amazon and saw the needed part for between $25-50, got one for 50 and it works great, I didn't have any motor problems however, the motor is out on my rear passenger window, probabaly looking at @250-300 to get that replaced, not gonna bother.

 

So did u buy a new window motor?

Lately my driver side window has been refusing to go down when I let that door heat up under the sun for too long.

 

To the guy having the problem, I fixed mine for $50, but I'm not going to tell you what the problem was or what part I bought..