Truck Body kit Design

The project is to design a wide arch body kit rendering in AutoCAD which I can later add in the measurement to scale the drawing and have the kit produced. I have four renderings which i need to be able to scale for production of the new kit.

I have renderings like the images attached which gives you the idea of what i am after - all drawings i have will be shared with you for this work.
When creating the images I do however want the kit to be original so whoever takes this on will have to change the kit slightly so that it is unique.