It doesn't take require much skills to be friendly. The staff at this McDonald's are the rudest I've ever come across, including the manager. I went to the drive-thru in the middle of the night, and they ask me to wait 10 minutes just to order when no one was in line. Then when they finally help me, they tell me that I can't order a burger because they just switched over to breakfast. And don't ask for extra stuff like tartar sauce on the side. The manager even murmured under his breath when I asked. I don't even want to know if they spit in my secret sauce.
I have had nothing but problems with the drive thru, since they made a two lane drive thru. You either don't get helped at the speaker box while those who came after you get helped or you sit in line forever.