If I may, I believe it might have wider market appeal if you were to remove any personalizing items on the car. Things like race numbers or decals. I've always found that with those things present, it narrowed interst far too much.
I myself personally, I wouldn't mind a number on the side of my car.
Once again, my wife disagrees with me, so no numbers for me.
I've gone as far as to remove out of date/state inspection stickers. Buyers are ALWAYS looking for a reason to knock down your price. It's so much harder to sell a car down here with a LA sticker than no sticker at all.
"That thar car aint frum 'round here, izit boyha?"