Revealing mistake: When Rita pulls the first stack of hundreds out of her purse, she puts it down next to her. The bill on top is very close to looking real, but the bill underneath is very fake looking. (00:44:15)
Revealing mistake: In the scene outside the airport Betty is seen saying goodbye to Irene. As she looks at Irene you can see the trunk lid of the cab open behind her. The open lid is over her left shoulder. A few seconds later after Irene leaves and Betty notices her bags are gone. She looks to the Cab driver who has them. He opens the trunk lid once again and places the bags inside. There isn't enough time for another cab to have loaded and driven off so it has to be the same cab in both shots.
Answer: The song is Roy Orbison's "Crying". Lyrics can be found at "http://www.lyricsdepot.com/roy-orbison/crying.html"
jle