I saw in the plugin forum he's looking for PSD files to play with. I have one of my old car. It's a simple 2 or 3 layer file but it's HUGE, 8mp.
I've uploaded for general use. As you will see when you load this in to Paint.NET using his plugin, the image is all "snowy". Something's borked for sure.
http://www.pixelsmack.com/incoming/filez/testFile.rar (32mb)