The first round of mockups was horrible as far as colors, design, layout, type. Everything about it was not "my style". You can see the first mock up I did below. Word to the wise, this is not how you should design a vehicle wrap.
After some sleep, I sent them the comp below. Not great, but it's a big improvement over the first comp I sent.
I have designed a ton of vehicle wraps in my day. Only a small handful of them I made the design go from the side to the back, to the other side and keep a flow. It is extremely hard to get a design to go from the side to the back, to the other side and have say a thick white line stay aligned for over 600 feet. Installation problems aside, its pretty difficult on the design aspect, specifically the back and the front. How do you get a curve to stay curved? You don't, it would never work. So I went straight on the back and front, it was just about the only way to get the design to stay aligned.