I have a bottle of this 3M product that I use to polish before I wax. When I got the bottle, the liquid had the consistency of honey. I've used it very infrequently. Today I used to polish off some swirl marks on a car with black paint. Shook the bottle vigorously for some time before applying it to a sponge. The glaze is now in a much more fluid form, almost like milk. I used a thin clean BBQ skewer to try to see if there is any thick goopy sediment on the bottom and found none. I used it anyway and it still works like the way it did when I first bought it: it got rid of the fine swirl marks. This is a product I've been using for the past 15 years and I am on my 3rd bottle, and they always liquefy into a runny fluid over time. What is it that is breaking down? I always keep the bottles stored inside the house and the temperature is always around 75F