Possible Clues:

• Late-night regular
• Five-night-a-week NBC star
• Nightly comic
• Carson's late-night successor
• He's visible a few minutes after the news
• Who once remarked 'You can't stay mad at somebody who makes you laugh'
• Comic / host Jay
• Jay who has Monday night 'Headlines'
• Host on the tube
• TV host with a big car collection