I'll second the warm water thing.
I've done many a spray-paint job on a piece of old farm equipment or even just a little tool box or something (where the paint is really just there to prevent rust), on a cold day. Stick a deep pot on the stove, boil it, take it outside, and stick a can of spray paint in it (no longer boiling, having a moment to cool). When the water is that hot it takes just a few seconds, removing frequently to agitate. As the water cools during the project, you lengthen the amount of time the paint cans sit in the water. I imagine the same idea could work with detailing products. With touch up paint, you could just heat a glass of water in the microwave, toss the touch up paint into the glass after removing it from the microwave, and get some nice flow that way. Heck, hot water out of the tap is probably plenty warm to warm that up (I only boiled the water on these rattle-can projects so that it would stay warm for the duration of a 20 minute project)
Keep in mind that many of these products may have toxic chemicals in them that can become aerosolized in a microwave. There's also the potential for metal components in packaging, or even in the product themselves that can damage your microwave. Personally? If it isn't a food product or something similar (like heating up a damp rag), then I wouldn't put it in the microwave. But that's me.