If the dealer thing is a sticker, it will usually peel off, as most stickers are vinyl. A slight heating will help. So if it is really cold out, try a hair dryer on it to heat it up. your fingernail under the edge to start it is good.
The sooner you take it off, the easier it will BE to remove it.
if the dealer thing is a plate/raised plastic, the dental floss will take it off, then cleaning off the residue with any cleaner, even a cleaning car wax will usually take off the goo.