I keep hearing a crackling noise coming from my exhaust when i'm lights when I been driving for a while. Making a noise like there are rocks rattling kinda. I heard this is a common problems on Gs. I should taking it in to the to get looked at right?

 

Yes, this is common.
Search the TSB section for more info.

 

https://www.myg37.com/forums/tsb-technical-bulletins/180963-tsb-rattle-in-main-muffler.html