It's a common rumor that Jobs doesn't have plates on his car. This article speculates that it's not legal, but Jobs (or his staff) just pays the $250 fine if he's ever ticketed for it. Some of the comments also speculate that Jobs' car has suffered repeated vandalism due to people stealing his plates, and that the DMV has made an exception for him.

http://www.iphonesavior.com/2008/09/steve-jobs-barc.html

In Pennsylvania, you can look up summary offense level driving/parking tickets for everyone via a convenient online form. I tried looking Jobs up, but California seems to wisely keep such information off of the internet.

Edit: There are 5 random cases with Steve Jobs in San Mateo that are the matter of public record, but California seems to keep all traffic information off of the internet. Compare to PA where a parking ticket doesn't go on the internet, but driving without a license plate does.

Surprisingly, yes. In California, apparently, there is a provision in the motor-vehicle code that allows 'celebrities' (for some definition of 'celebrity') to drive around without license plates.

won't driving without a license plate just single you out as a celebrity then?

Yes, but the stalker/paparazzo/divorce attorney won't know which celebrity.