The best way is to use a heat gun on low, or even a hair dryer on high. Don't get too close to the paint, though.
When it's all gone, use "Goo Gone" to remove any traces of the sticker. (avail at your local Mall Wart)
After a few washes and waxes, I bet you'll never even see it was there.
Try it on one of those underhood stickers first, like the stupid "caution" stix, tellign you to stay away from the fan.
I removed an entire set of sun-baked, 20-year-old stix and stripes from my old camper using a heat gun. They can be dangerous, though. Very hot on the paint if not careful. Had a couple spots where it "buckled" the aluminum skin. Looked SOOO much better, though.
No pix, however.
Greg