Re:Concession window question
Its a matter of preference for up or down and side to side...I'm tall and all my equipment is at least 36" on the inside of the truck so I had to put the windows 36" up from the floor inside the truck. Works ok BUT its a bit high for anyone standing outside the truck...or anyone who is short. I like it because it fits for me and because I can easily lean over the equipment and reach, etc. but its a stretch for anyone who isn't tall. If you're not planning on putting coolers, etc in front of the windows and are just going with countertops then I'd definitely try and get them as low and reachable from the ground as you're comfortable with. Remember though-the lower they are the more of an awkward reach and challenge it will be for you. Likewise the taller they are.
Mine slide side to side and it is tall...but its manageable for me and the guests