i was wondering if a fitment of a 20"x9.5"+17mm front and 20"x11"+19mm rear would fit my gs? thanks

 

that would fit quite nicely. minor mods will have to be done, such as rolling the front fenders and shaving/rolling the rear quarters. also depends on how low u go and camber settings
you should check out Vipstylecars.com and ask around there too. they are more fitment orientated than here

 

thanks for the info.

 

Yes it will fit depending on tires and suspension, but some work required for sure.

Many are running much more aggressive like myself.