I've buffed worse out of saddlebags on my motorcycles that were from my boots.
Some decent spray detailer or some polishing compound and a soft cloth will make short work of it if it's not a scratch through the paint..
Don't get rubbing compound. It has to say polishing. I like the 3m stuff in a small gray bottle, but there's plenty out there that work. Then wax the beejesus out of the paint on the car and it will help prevent some of that stuff (and also give a tiny bit of protection from that sharsh desert sun).