Wash the car again (or the places you want to buff off) to remove any dust from, and buff it off. I did the same mistake and listen to the instructions the product came with and it was hard work to buff it, could see the spots following day we missed.
I don't think that it will come off with regular washes (at least in reasonable time).
Some questions are better answered at http://www.vwwatercooled.org.au/f22/