Slight nit: No, he didn't have temporary plates. At the time, a new car was allowed to have no plates on it at all in California. So, you couldn't track which new (black) car on the road was his, even if you did happen to see him in it. (And I think the limit was 6 months, not 2, but whatever.)
The regulations have since changed, and now all new cars don't come off the lot without a temporary plate with a large, lovely temporary number on them, but that only came into effect after he had stopped driving.
Source: I live a few blocks away and regularly passed by his sequence of cars in his driveway.