Here's some cars I was experimenting on today with weathering techniques and some graffiti. I found these MDC Roundhouse cars cheap at my LHS, so thought I would work on them and see what I could do. They're too late for my time period (1960's) and I'm not a big fan of graffiti, so I'll probably toss them on eBay, but it was a good learning experience and I feel much more comfortable with weathering now. I used acrylic paints to start with and then progressed to chalks. In between each application I used a layer of Dullcote, then more chalk, etc.