FYI...Tried to upsize to a Group 24 AGM battery in my 2011 G37X sedan. No Go. The size difference is no problem. The tray will accommodate the larger battery. But, the terminals are in the wrong position. The cables did not reach.
Tell me what I did wrong.

 

You bought a group 24 battery, not a group 24F battery. Same battery but reversed polarity. It fits fine you just have to be particular about the where the cable sits so that the cover will still clip shut. Don't have the fuse block directly under where the battery cover latches.

 

was the stock battery not sufficient enough?

 

The battery was weak/failing and causing problems. Last week it wouldn't turn the engine over at -7F. Wanted to take the opportunity to make it better. The car has always turned over kinda slowly. The dash lights go off and on when the starter is turning. And has recently been clearing some memory settings on colder mornings. (remote key functions) Maybe it's a starter problem?
I think using a 24F is the correct answer for the fit question.