MaryB:
If you will, I`d like to impart some advice. Whatever dealership you purchase the car from will not handle this how you expect them too or how you`d fix it. If this is a used car dealership, good luck negotiating the price because they don`t really care that there is a small blemish like that, it is a used car, paint chips are a different story, but still present your case because you just never know how badly they want to sell it. If you`re buying a new car from a dealership they may knock down the price by a few hundred dollars. However, either way you look at both scenarios the dealership is going to think that you`re nutz. Unfortunately, the majority of modern dealerships are run by people who think they know everything about cars just because they `work at a dealership`. The number of true automotive enthusiasts, in a dealership, is not as great as one would think. Don`t forget that a dealership is a business, a business that wants/needs to make money. With that being said they may just look at you and tell you to move on, every car has a buyer. If you really want to search for a discount, start inquiring about how long the vehicle has been on the lot, how much they have in it, compare vehicles within 150 miles of you via the web for negotiations, and mechanical maintenance if this is a used car. I`ve spent time working at a used car dealership, oh the stories I could tell, and the insider knowledge I could share; it would put most used car dealerships out of business, I know it all.
If you get the car, this is an issue that you or a really good bodyshop should rectify, there are not many people who will fix it to your satisfaction. If you have to wait until you fix it, clean the spot well and then cover it with a wax or sealant. I would personally clean the spot well, give it a good polishing, fill in all the gaps the poop has created with a Duplicolor pen-like clear coat, and then seal it/live with the mark, I`d personally never sand any body panel unless I paint the entire panel. A spot fix hardly ever ends up matching the look of the factory paint.
Good luck with everything! And remember to do your homework, knowledge is power, especially in this circumstance.