I'm currently using Transparent Black as a wash for things like grilles, etc. I have a few other Wicked and Auto-Air colors that I use for hand-brushing. I have never thought of using Future as a thinner for airbrushing, though. Gonna have to give that a try! One of the advantages of using Future is no "dry tip". It really helps lay the paint down. Supposedly a product called Quick Shine multi-surface floor finish can be used in place of Future. I purchased some, but have not tried it. It seems that some people are having difficulty finding Future in stores.
Thanks for sharing that info!