Previous —slightly related— thread.
I designed a wrap for a RAM pickup about 10 years ago. Looked great, and didn’t show much degradation over 5 years. The design didn’t cover the entire truck — just the doors, exterior bed, rear gate and a line of text on the hood. Did it that way because that was the design I wanted, but it was also cheaper.
Did the measurements myself, and used stock photos and photoshop to create the four art panels (sides, hood, tailgate) which the wrap company printed and applied. Of course the wrap companies offer complete design services. They have templates for most vehicle models.