When i bought my car in 01 They dealer put some stupid GT stickers on the side of each door and on the back. It was a red and white flag and GT in the middle, 3 of the f**kers!!!!!1
Then after much mockings of my m8s, I tried to get them off, took my over an hour to get them all off and I used a hair dryer to try and heat it up but it kept coming off in parts and leaving a mess.
But hot saopy water will help getting rid of anything left behind, I also used it to remove the Renault garage stickers in the back window!