I would nix bombing them. I would wait until the evening hours when it is cooler out to search for the nest. When it is around dusk, wasps will come back to the nest and it is during this time that they are less active.
Before looking for the nest, make sure you have protective clothing, gloves, and a hat on. Remember wasps can sting you over and over again. Do a search for the nest. They can be almost anywhere. Look in the door hinges, trunk if it leads into the car, any possible opening or crevice. Once you locate the nest, spray it with an aerosol wasp killer. The spray has a distance of 15 or 20 feet, so you can keep yourself far enough away to protect yourself. Wait a little while and check the nest. If you do not see any wasp moving about, cautiously remove the nest. If you feel it might be a little more than you would want to handle, look to a professional for help.