A year or so ago I went through the drive-thru at Taco Bell, was the last customer of the night. I offered the guy at the window (manager on duty, I think) a cold beer and he accepted.
Next thing I knew, I had a bag full of everything left over at the end of the night!
Burritos, tacos, wraps, way more than my original order!
Always offer your drive-thru operator a beer if it is close to closing time.
VVV