If you're serious about this you just have to do your research. Find an area with a lot of blue collar businesses like automotive repair, construction, welding, and other labor type stuff. Know the variety of ethnicities and what food options are nearby. Maybe if you know a few owners in the area, ask how they think a new roach coach would do. While doing your own ethnic creations is definitely cool, you'll still need to stock donuts, bagels, coffee, soda, gatorade cigs, bad for you chips/prepackaged pastries (hostess things), and make some sandwich/subs the night before and syrann wrap them up for quick purchase grabs. People are more likely to buy something they can see already there rather than looking at the menu. You might get people ordering a burrito or something from you and also impulse buying a small $3-4 sandwich, a soda, and a donut all at once. The roach coach guy that goes up and down OBT in orlando (road full of drug dealers, hookers, automotive guys, and other blue collar shops) makes a good living and he doesn't have anything fancy. Just bad sandwiches, hot dogs, donuts, bagels and snacks/goodies. My dad was telling me that guy makes real good money. I know you have high standards and everything but remember to somewhat compromise your ultimate vision. You don't need to have great food to be a really successful roach coach. I'd wager the most profitable ones aren't that great. It's all about the location and businesses/clients you have