The Thomaston planning board gave approval April 21 to a $15 million to $20 million auto dealership on Route 1. And the Board also gave unanimous backing to another food truck on the stretch of Route 1 near Rockland. The Board approved New County Road, LLC’s (Jack Quirk of Quirk Auto) application to build a 31,000-square-foot dealership at 218-222 New County Road. The estimated cost is $15 million to $20 million. The project is expected to be co…