It's already too late. My house got egged at Labor Day and some of the egg got on my wifes car. I didn't notice it until it ate through the paint. Like you mentioned, it felt rough. As I tried smoothing it out, the paint just flaked right off and left me with a rough primered surface. If you can feel it being rough, it's too late.
2014 Mustang GT Premium: Ruby Red, GT500 exhaust/valance/spoiler and Roush Upper/Lower grills and splitters
1987 Camaro IROC-Z: 350, TTops, Leather, Bose and only 20k original miles