Mid-Lin has the distinction of being the only trailer park listed in the greater St. Louis phone book, but it wins our "best of" for all mobile home communities, ranches, villages, acres, estates, courts and manors. The trailer park that's not afraid to call itself such is located near the intersection of Midland and Lindbergh (hence the name) and is full up at the moment. If you're lucky enough to find a vacancy at Mid-Lin, one of your questions about the property may be charmingly answered with another question in response, as we experienced. "How many trailers in the park?" we asked. The manager's reply was a classic bit of salemanship: "What difference does it make to you?"