My dad sprayed our old camper yellow, and our red Fox was in the driveway...
Up close it looked looked a ladybug! The yellow spots were EVERYWHERE!
A razer blade quickly took care of the glass and mirrors, and we re-waxed the car
and all the spots came off quite easily. Don't know if that will work if the car hadn't
been waxed in a while, but the yellow paint spots were on the wax, not the paint.
The plastic, tires etc also came clean with our favorite black treatment at the time.
Like I said, it was a few years ago, so I don't remember what is was (Armor All?).
It's worth a try, especially if your Fox had been waxed previously.