19's
 

I know I can go 18's no problem on my '98 GS4, since the L-tuned already comes with it. I have Lexus 17's on right now. I can't decide if I should just play it safe and upgrade to 18's (by the way, what is the recommended tire size for that?) or should I go with 19's. I know it looks awesome, but I also heard that the tire damage is too frequent and the ride really gets rough. How bad does it get? I don't want to feel like I am in a Civic again. What would the effect be if I throw L-tuned shocks and springs in the mix. I know the benefits to handling, but would it help or add to the roughness of the ride? Thanks.....

18s: 245/40/18, 275/35/18...with l-tuned, the ride still retains good level of comfort...

19s:245/35/19+275/30/19....a bit rougher, slightly more limit on tyre chocies, and higher prices....but, as you said, looked awesome..

go to a cl meet and test ride yourself for your own taste, some like 18s, some got to have 19, or even 20s....