MHL- I have a very similar set up to U, with 17x8 and 215/45/17 falkens zies 502(except my car is a 97). Now, the MY98 & 97 is basically the same car and thats why you may rub in the back. I know the front of your 98 has a bit more space in the wheel well, but the rear may be the same cause if I have 2 or more people(regardless of weight) and I hit a bump or dip, I hear a slight rubbing. So I upgraded my suspension(my stock susp. was really bad anyway) with Bilstein rear and Konis front. There was an improvement, but if I have 2-3 adults in back(which i rearly do) it will rub a bit(but I have a 5th wheel and stuff in trunk too).
Now after careful consideration(including rolling the fender, new springs etc.) I realised that it is better to just get 205/45/17 tires or get 17x7 or 7.5 in my current style.
NOTE: U have to compromise somewhere; guys with 215 and 225 tires are runnig 7 or 7.5" rims. If you get 8", which is a bit too big for our car's set up, u have to go narrower tires.
Thing is my wheel don't come 17x7, so I will get a smaller tires next change. Plus I don't have a full load too often.
So, you should upgrade the suspension for it will improve the handling greatly and the ride is just as taunt as my T-5 if not a bit better. If you have a GLT, you will be in for a suprise, but you and your passenger will get used to it. PLUS, since you're running lower profile tires you're abusing your stock suspension more that is it used to; the Bils or Konis are made for the extra abuse. get the upgrade and you will see the difference. good luck,BD