They fit that way? GTA offsets are 0mm for front and 16mm offset for rear. The reason is the rear axle is/should be wider than the front axle so the rears are offset to hug it more.
Found this info on here url
http://www.thirdgen.org/techbb2/show...ght=gta+offset :
If you put the rears on the front, they'll contact either the spindles or the caliper, I forget which. You can put the fronts on the rear without any problems, but if you lower the car, it could be necessary to roll the inner fender for additional clearance.
The fronts probably cost more because they are more popular. Most accidents occur in the front of the car, plus many people buy 4 fronts for non-fbody applications.
Anyways, I'm all tickled when I take my car in to have the tires rotated and the places just try changing the rims around and the rear ones won't fit one the fronts and vice versa. One time after a 1 1/2 hour wait one place told me they wouldn't change them cause they had to be taken off the rims. If they didn't have to be swapped off the rims I would have just done it myself.