I have both 845 and 915. Haven't used the 915 yet, but I applied the 845 to both my car and my parents' 2000 Honda Accord a week or so ago. Since then we've had a lot of rain, chilly temps, stuff like that. Supposed to get a snow system this weekend, a light snow mix possibly next Tuesday, then it might be a few days or more before it warms up and I get the chance to wash again. So it will have been a few weeks since their last wash. Both cars were beading just fine the other day when it rained, even though they were both dirty. If 845 is still going strong when I go to wash both cars, I will be sold. I will say that it was stupid easy to reply and remove. I always like that. :dblthumb2:
Incidentally, I applied M16 to our 1990 Accord at the same time I applied 845 to the other two cars, so I am curious to see how it will hold up to all this nasty weather as well.