The G37 seems like a very reliable car except ealier models (08 ~ 11) might have this rear timing gasket leaking problem, which is not common but if happens will cost $2~3k to fix. And apparently lots of people have heard about it:
https://www.myg37.com/forums/engine-...sket-leak.html

I am wondering if the 2007 G35 or M35 would have the same potential problem, since they are using the same engine.

 

 

different engine, not a typical issue with the VQ35. the 35 may have valve cover gasket issues which are less costly to repair, but shouldn't have the same timing cover gasket failure potential (which is still very rare, but possible).