If the stickers have been on for years, which they appear to have been based on your post, you will probably have discoloring.
I wish people would not put stickers on painted products. Put 'em on the windows, but not on the paint, and not on the bumpers of cars. I won't buy a TT or a car with stickers on it unless it was a heckuva deal, and I saved enough for a new paint job.
Decals are different. They still will leave discoloring, but Im okay with decals instead of all the little stickers from places people have been.
Mike