I have an 89 GTA and want to put American Racing 200R wheels on the car. They don't have 16" but the dealer say no other sizes will fit. Is that true? I really like those wheels and will run 15" or 17" if they will fit. Any help??

 

Either your dealer knows something about those 200R wheels I do not know (limitations in available backspacing options for instance) or otherwise, your dealer is broken and you need a new one.

In the stickies you will find how to determine wheel/rim combinations that fit.
I have seen pretty much everything from 14" up untill 22" on these cars and think 17x8 with 245/45 R17 tires fit these cars well optically.

Should be a readily available size tires as well.