Just removed the dealer sticker on my Z yesterday. I had a blow dryer in one hand blowing on the sticker as I peeled away slowly with the other hand. This method left a lot of glue residue that I removed using a soft towel and rubbing alcohol.

Goo Gone works great to get the glue residue off as well and won't damage the paint/clear coat.

I told my dealer to take it off and make sure it was done right or I wouldn't buy the car. Not sure what they did, but it was gone without one little blemmish. Like I told them, I may buy the car from you, but there is no way in hell I'm advertising for you.