Is 12MM x 1.25 the correct stud size for the g35. I have some wheel locks in that size and was wondering if they will fit the 07 G. Thanks

12 x 1.25 is the correct size, but the lugs changed for '07, with a big flat washer that seats against a corresponding surface on the wheel. In addition, there are different types of tapers (conical, spherical) for the angled contact surface (I know, not very clear...). So even if the diameter and thread pitch are correct, they need to be otherwise compatible with the wheel.

Search on wheel locks there are several threads including some with pictures of the correct type for '07s.