Pop superstar Michael Jackson met business superstar Lee Iacocca, and the conversation must have been a thriller, because no one's saying what was discussed. The meeting was set up backstage at a Jackson concert Monday night in Auburn Hills, Mich., after one of Jackson's attorneys wrote to the Chrysler Corp. chairman. "Michael had read Lee's book (`Talking Straight') and, you know, Michael is mentioned in the book," Chrysler spokesman John Guiniven said. In "Talking Straight," Iacocca defended the $20.5 million he made in 1986 through salary and stock options, writing: "$20 million sounds more like Michael Jackson's income for a weekend than the annual pay of a guy who can't carry a tune in the shower." Iacocca's estimate was off the mark if Monday night's show was anywhere near Jackson's standard. Net income from the concert was $125,000, which Jackson donated to the Motown Museum.