These may be the second most detailed cookies I've made (second to Rapunzel). I'm mostly happy with them. I think my biggest problem was in not flooding full enough so they caved in a little as they dried. Oh, and that dent from my finger (oops!) on the cab of the bottom truck. Oh, AND how I forgot that I had made regular truck cookies and had it all in my head that I'd baked fire trucks. So yeah, you can totally make a fire truck from your REGULAR truck cutter as well. ;-)
All my icing is flood consistency, 18-20 second icing. I didn't pipe around the borders, but you could. Here's how I did it.
Note, I highly suggest that you don't transport these with the ladders attached. I broke a ladder putting them in the box.