I'm with Coltsfan1 (and not just because I too am a Colts fan). I bought my TTA brand new, and did not put the decals on. I left them off because I wanted to preserve them, and also because I thought they were a little ostentatious. But at the 25 year mark, the time was right to apply the door decals, because I was afraid they might deteriorate to the point I couldn't separate them from the backing without tearing them, and also because the car is now a classic and it needs to look like one! (I'm with Robert on the windshield; my "Pontiac" sticker is still in the box).
Regarding placement of the door decals, I just looked at pictures on the net of the official Indy 500 pace cars, and copied them.