Here is a mock-up of a Fire Truck I'm working on... It's very rough right now and I'll most likely end up starting over with actual pictures of the engine to model from. I was going to model this in 3Ds Max, but after not using the program for a few months I honestly don't know where to start...
The nice things about SketchUp is the ease of operation, there's no hidden tricks and everything is pretty straightforward... and the best part, it's just like riding a bike, you never forget
Here's another shot of the rear.
I'm hoping to incorporate the steering limits to the model and we're going to try to use this for "pre-plan" to see if the trucks are going to have any issues entering some areas of the community.