If you choose to use the drive thru, please follow the signs and go around the row of parked cars to get in line. I've seen too many times of near fist fights because of people trying to cut in line.
By far one of the busiest drive thru's I've seen, 4 days in Denver, 4 days I opted to park & walk inside and each time I was back on the road before the last car in line when I arrived.