Exhaust tips are unique to the TTA however those, like the badges are easily changed.
From what I have seen/read/learned the only givens on a stock car would be the nose badge, the sail pannel badges, the badge between the tail lights, the Indy wings, and the tips. Over time all of this is subject to change depending on what was done to the car. Door and/or wind shield decals could have been added. TURBO fender emblems may or may not be there.
Another thing thing to throw out, the white stipes in the door handles. I don't think other TA's or GTA's had them but I will have to admit I never actually went looking.
Brent