-sigh- I really should just copy and paste the formula for what to charge.
Find out what your shop overhead per hour is (non-graphics, non-labor costs for a month divided by 30 days divided by 8 hours) lets call this "O" ... make sure to also add in equipment wear and tear into that.
take your overhead add it to your labor costs for graphics (lets call labor L) and multiply times hours it takes to do a vehicle.
(O+L)xhours=labor costs (C)
materials x margin (for oopsies, miscalculations and other hidden material costs like
paper towels or whatever) = Material costs M
C+M= your bottom line. factor in time to deal with customers, art fees, and other costs ... you have your going rate. need some negotiation wiggle room? throw a margin on top of your bottom cost ... that is your top cost you give a customer first.
And P.S. you were WAAAAYYY too kind to actually answer this question lol.
Business 101.