Welcome to the GRIN Group....
I agree with Greg...don't worry about the value....it will be a long time before our cars will become collectibles....enjoy your new Challenger and make it yours...Greg has! Besides, a rear spoiler will only increase the value, and you can always take it off at a later date by replacing the deck lid or reworking the holes left behind should you want to remove it...
ORIGINAL: Paladin06
Welcome and congrats on the new Challenger. I don't think putting a Mopar spoiler on will hurt your value. The looks are part of owning the car. Kinda like being a rock star. Now, lets see the car and the GRIN.