Agreed...I had the T1R's on my mind. I just don't know yet if I want to either:

A) just replace my rear wheels with the same brand/model and just go with the wider 9.5" (I currently have 8.5" all around) version and upgrade to the T1R' for those rear wheels (Maybe cost me $1200 in total)

or

B) wait longer (maybe MUCH longer) and buy a brand new set of lightweight 3-pc wheels; staggered setup. This route of course will be MUCH MUCH more expensive (Maybe cost around $5000 in total) and I'm not sure if I can justify this cost as of yet.

...we'll see.

 

I'd go with A). Have you thought about going to something like 18"s? Tires are A LOT cheaper than 19"s or 20"s.

If you want lightweigt, just get RPF1s

 

next (power) mod? custom exhaust piping with X-pipe. Then get an SAFC to dial in your system.

 

If you're looking for performance wise, I would choose 18" wheels as my desired size. You really don't need wide tires necessary as I think for an NA GS with less than 350 rwhp, 275-285 size will do just fine in the rear. The tire choice makes a big difference. For me, I run the stock IS350 wheels and run either Yokohama Advan Sport, or Bridgestone Potenza RE-o1R. They are a littel pricey but will bring a smile to your face when you are planted going into a deep corner. You can opt. to go with a less aggressive tire, but for me, these two tire choice have been great for track and street driving.