It looks like Bob Dylan's favorite sound these days is the clink-clink-clink of pennies in his retirement piggybank. Why else would one of the world's preeminent songwriters and stewards of music go all commercial on us? Cadillac announced recently that it has teamed up with XM Radio and the magnificent Mr. Zimmerman to move its Detroit-branded luxury iron. Dylan's "Theme Time Radio Hour" show on XM satellite radio is excellent listening, and since XM is now a standard feature in the Cadillac Escalade, the brand was able to get Mr. Dylan in a TV spot for the luxury SUV, as well as create a Cadillac themed episode of his XM show. The Cadillac brand has inspired many a song, and some of those will be featured on the specially-themed edition of Dylan's XM show. We can certainly understand Dylan's desire to cruise around in the lap of luxury, and the Escalade is nothing if not luxurious. And when you've paid your dues, you deserve at least a few nice things. Don't bother wasting your breath with jeers either, Dylan heard it all in '64 when he picked up an electric.