So, I;m on a budget and wanting to put in a stereo to my new 06 g35 coupe. The double din costs more than the stereo I am looking to buy so I was wondering if I just pulled the system apart if I could use a dremmel tool and sand paper to convert the old din into a "double din." Not sure if the AC controls are different on the double din and thats why I couldn't do this or not. Thanks.

 

It has been done, to varying degrees of success.

Go to google, search "g35 diy double din", read.

 

The AC controls are the issue. There is a large circuit board that is basically the size of the entire center console. You can cut the plastic face and fabricate it to fit a double din, but this circuit board will be in the way, and the circuit board is necessary to control your ac.
I have seen a few ways around it, but they wont really save you any money unless you get lucky and find some hard to find parts for cheap.