Got the book on the making of 'The Blues Brothers' by Daniel De Vise last year. Bit more detail about the movie (more than Bob Woodward's 'Wired' from '84 or so.), and De Vise notes that the movie is more highly regarded now, than when it was released. Even noted film critic Roger Ebert (Chicago boy himself, IIRC) made the claim back in 2005, the movie's 25th anniversary.