Go to any of the BBQ island places and look at them, they are made of the metal 2x4s. I went to a place that sells them and thoroughly looked inside each one to see how it was built and took notes. There are track and there are stud pieces the that slip into the track. 1-2 backerboard with 16"...
I would build it what size best fits you, when I sold my last house that had non permitted additions, I had to disclose there was no permits for certain things, but I was not subject to any penalties. I also sold my house for over asking price!
I did, out of steel 2x4s, backerboard that I stuccoed on three sides and put cultured stone on the front, a marble counter top with BBQ and refrigerator. Mine is propane and three bottles fit under the BBQ no problem, have not even gone through 1
Of course that's what we are on here for, there is a standard size deminsionally that I got of a US flag website so it looks proportionate, I just enlarged the size to fit my needs, the stars are vinyl , not painted, just seemed easier.
I am in the process of building a fake service station on an empty wall in my garage with some reclaimed wood, old windows and a fake roll up garage door. I wanted to get a large picture to put behind a window mounted in the wall to look like you are looking in an old drag race shop. Anyone done...