My father-in-law owns a carwash business. I want to take advantage of the foot traffic by selling sandwiches using frozen cured meats like cooked ham. How much nowadays are simple ham and cheese sandwich at your kid's school or your office cafeteria? What other quick snacks can you suggest I offer?

Ham sandwich, hotdog sandwich and on sticks, burgers, tuna, egg, bacon, the list goes on. You can offer these so your customers will have lots of options and if you want, you may want to add finger foods like fries, cheese sticks or quail eggs, squid balls, chicken balls, etc. Just make sure to coordinate the prices and choice of snacks to be offered with the kind of market your father's car washing business is catering to. :)