"what ever happened to the traditional laurel wreath for the podium celebrations? I see them draped around many a winning driver in Grand prix podium pictures from yesteryear, but the ritual seemed to have disappeared in recent times."

The traditional laurels indeed have been long gone. At some time during the 1980s it gradually disappeared. I have been looking through a few books on Formula One history and the most recent winner with laurel wreath I came across was John Watson when he won the USA-West Grand Prix at Long Beach in 1983. The reason for getting rid of this tradition? Probably money, since the wreath kept quite a few sponsors' names out of view.