Knock yourself out. I think what the other sign pros here are saying is that it's much, much harder than you think to consistently letter trucks (and every other weird thing sign makers work on) profitably. I don't know how much you paid for the plotter, but for lettering one truck, you will lose money. You will need vinyl to put on your truck, not super expensive, but not cheap, especially when you are throwing away your tenth yard of balled-up sticky crap. You will need a computer to hook to to the plotter, and some software to run the thing. You will need a roll of transfer tape and a method of applying it, which may require additional expense. The type of truck you have will determine the type of installation you will do, which will determine the kind of vinyl you use, which will determine the tools you use. Seriously, that quote might have sounded like a lot, but it is a lot harder than it looks. But, like I said, knock yourself out. Get squeegees, alcohol in a squirt bottle, paper towels, masking tape, a tape measure, xacto with #11 blades, a heat gun, cordless drill with a nice drill holster, little giant ladder, portable scaffold, arc welder and a powder blue '68 Impala and send them to me when you are ready to tear your hair out in frustration. You may succeed at this truck, and I hope you do, but for god's sake don't try to make money doing this. It isn't worth it.