What's coooking in YOUR tank?

It was a beautiful Christmas Eve day in Beverly Hills. One that only Southern California could provide. Blue skies, 75-degree temps and no smog.

The kids and I decided to cruise around in our 2007 Hyundai Elantra loaner to see what the rich folks were driving these days. We passed huge houses after gigantic palaces -- hey, was that the Playboy Mansion back there? -- checking out the multitude of rides in the cobblestone driveways.

There were the expected Mercedes, Lexus, BMW and Acura, of course. Those, I suspected, were the cars the kids drove home for the holiday. But we also saw a hefty amount other exotics, Ferrari. Aston Martin, Lamborghini, a couple Rolls Royces and several Bentleys -- all lined up outside as the families did their holiday things inside.

Soon, something strange happened. I began to get a whiff of a barbecue grill, or so I thought. "Hey, somebody's grilling steaks for Christmas Eve," I remarked.

The next block brought a strong smell of French Fries, followed by a distinct fried fish aroma.

"Boy, it must be a tradition for people in Beverly Hills to barbecue on the holidays, " I said as the kids picked up on the fried food fragrances.

Just then it hit me. Up ahead, leading us through the immaculate, posh neighborhoods of the rich, was a beat-up old (early '80s) Mercedes station wagon.

On its back window was a bumper sticker that read: "Powered by vegetable oil."

We smiled, having finally got the answer to our original question.

So that's what the rich are driving these days!