After the Mississagi, I decided to head home. It looks like it was going to get nasty again.
Sure enough it did, so I decided to stop at a rest area for a while while the rain blew over. As I was leaving, I saw the rainbows. Well in this case, a double rainbow. Sadly, it rained on my lens and hence the spots.
I cleaned off the lens and re-situated the car so that the rain wasn't blowing right on the camera. The rainbow was still there.