I've seen some businesses adopt the ice cream truck strategy: They go wherever the people are.
I think that it would work , but you may need to find you a place to set up where the people can find you. I would consider being close to the mall area where people generally look for the merchadise that your selling. If you get the word out, I don't see why people wouldn't stop by to see you. With all that said, there are a few things you may want to consider. 1. Storage of the vehicle after hours. Gas is a issue, but if you go to one place and park it's just like anyone else going to work everyday. 3. weather! If it rains, for an outside business, it pours... These are just a few, but I think it can be done!!!
Hope this helps!!!