I'm about to pick up some 2004 Toyota Corolla OEM 15" Alloy Wheels and Tires and was wondering if they will fit on my Celica without any problems... any help would be appreciated before I waste my money.

Here is what they look like: http://sandiego.craigslist.org/pts/68738148.html

Go to tirerack and find out what bolt pattern and offsets that fit the car.

I did it for you for the Corolla S. 100x 5 and 38 on a 7 inch rim - same as a 6gc.
They fit. But, if its not from an S, you may want to go to the website and choose the applicable car.

Good luck.