Mystery Woman: You contemptible pig! I remained celibate for you. I stood in the back of a cathedral, waiting, in celibacy, for you, with three hundred friends and relatives in attendance. My uncle hired the best Romanian caterers in the state. To obtain the seven limousines for the wedding party, my father used up his last favor with Mad Pete Trullo. So for me, for my mother, my grandmother, my father, my uncle, and for the common good, I must now kill you, and your brother.
Police Dispatcher: Use of unnecessary violence in the apprehension of the Blues Brothers HAS been approved.
Elwood: What kind of music do you usually have here?
Bartender: Oh, we got both kinds, country AND western!
Elwood: They're not gonna catch us. We're on a mission from God.
Answer: It was a double, and the "making of" documentary on the DVD shows this.
David Mercier
To be fair, John did do a lot of flips and dancing as Jake; just not all of them in the movie.