A day after Downtown Investment Authority Board Member Dane Grey tendered his resignation, he offered the city agency a parting idea: give his firm a multimilion-dollar contract to overhaul downtown parking. Grey presented an unsolicited proposal in a meeting of the DIA's Strategic Implementation Committee on Oct. 8 that would give his company, Elite Parking Services of America, a 30-year lease on seven city-owned parking garages, on-street parking downtown and any future city-owned parking garages. Elite…