I work a BMW prep-center and actually we had to do on a brand new car today, all you need is a heat gun after you cleaned the area just heat it from a distance and it will disappear if it hasn't been on for very long time but be careful don't get too close as you might ruin the clear coat. The supagard kit that we use includes a foam to remove fairly fresh drops and works well. It's quite amazing how the heat gun can restore it but I'm not convinced leaving on the sun as others suggested would do the job. Hope it helps
