I Googled all kinds of strange stuff. This one makes the most sense to me. If it's in fact water based, I would start by washing it (you might want to look into that first, but the longer you wait...). If and when you go the Goof Off route, dab a very small amount on a rag and just work the road paint off--I would just use a paper towel with a dime sized drop of Goof Off and my finger nail at the same time to "scrape" off the overspray. Then wash it off thoroughly and wax. Goof Off is great, but just be careful--if your factory finish feels like it's softening up or your rag drags big time QUIT.
Damn.. should've got right on it when she did it. Maybe try mineral spirits? I've used it to get gas stains off of my white Jeep around the gas cap. I'd do this as a last try though and try it somewhere out of the way to make sure it won't damage the paint.
We had a little of it on our 2005 Pathfinder soon after we bought it, and I was able to pick each little drip off with my fingernail and/or a plastic scraper. The only parts I couldn't get off were the ones that were in the undercoating-type stuff in the fender wells. That just had to stay there for the most part, but it didn't really bother me very much.
I was going to say clay bar, but you already said you tried that. Castrol Super Clean would be my next step. I mix with 25% Super Clean and 75% water in a spay bottle. You might try it full strength, but wear gloves. It will eat the skin off your hands.
Thanks guys. It has been a while. It happened yesterday morning when she left for work. We didn't spot it until later that afternoon. The 95 degree heat had already done it's damage. I am just going to try scraping it off with my finger. I don't know how the paint will react to chemicals. The car is still fairly new and in good condition, I don't want to mess it up!
To rmodys: I have been busy. I still come on the site, I just don't post. I have been working in my yard, it's my new project. It is a new house, so there is a lot to be done. I will make an effort to come on more. ;-)
you could try some Total Prep. I get it from Advance. It's paint preparation stuff but it takes off everything except factory finishes. It's pretty sweet and at least for me, never has harmed the factory paint or clearcoat