Warning: you're about to read a comment from someone who's been building trucks for fourteen years.
It's a good start, but to have a great start, move away from the LEGO truck style. Unless you're building a truck like a MAN TGA or a Scania. For a more North American style truck, look at popular commercial chassis like Kenworth, Peterbilt, Mack, etc. Also, check out web sites of towing companies to see what their rigs look like. A great site is www.oharetowing.com. I got inspired to start building tow trucks from them. I definitely see potential from this truck.