As much as I like the second gen GS, the factory wheel fitment leaves a lot to be desired. It took me quite a while and quite a few times of pulling wheels off and measuring to find a set of wheels that met all of my requirements.
I wanted a proper fitment, both wheels and tires, as well as wheels that were manufactured in Japan. After talking with a few local shops, I gave up on them and went with Tire Rack for the speed and ease of ordering.
The final specs are:
Enkei Racing PF01
18×9.5
18×8.5
Sumitomo HTR Z III
275/35ZR-18
245/40ZR-18
Now I just need to get this thing a bit closer to them. That wheel gap is terrible!