Like most of her fellow suburbancommuters, Joann Warnke begins the workday in a somewhat frantic fashion. Have a quick cup of coffee, let the pets out for a run and make a frantic search for the car keys, which always seem to be lost. But for Warnke, the elusive keys on this day, as on many days, are to a silver Cadillac limousine -- definitely not your basic commuter vehicle.

Warnke, who lives in Cabin John Md., has been for two years a driver for the Watergate Limousine Service which provides a fleet of two Rolls-Royces and 25 Cadillacs for well-heeled and often well-known clientele.

Heading into the glare of the rising sun on one of the mornings after she has driven the Cadillac home with her, Warnke recalls how the love of driving has been with her since an early age.

"When I was 4, my parents saw a tiny, blond head attempting to peer over the steering wheel of the family sedan as it lumbered down the driveway and onto our street," she recalls. "At 9, a playmate and I had figured out a way to start and shift the transmission on a neighbor's car that was up on blocks and without wheels. I think you could say that it's in my blood."

While it would be easy to become star-struck by nearly every passenger who passes through her limousine's doors, Warnke maintains a professional attitude and tries to go along with each client's mood. "I treat everyone the same, and really do enjoy talking to them. But generally, I remain quiet until the passenger feels like talking."

The names of those who haved grace the crushed-velour seats of Warnke's Fleetwood read like entries in Who's Who, and leave a trail of impressions that could fill a book.

Actor George C. Scott, she says, "was one of the most refreshing people I have ever met because he wasn't a pompous ass."

Jean Stapleton, who portrayed Edith Bunker in TV's "All in the Family," was "so vastly different from her television character that it was shocking. She's a strong women's rights supporter and extremely articulate."

But of Larry Flynt, publisher of Huster magazine, she said, "I just couldn't drive him; it was a matter of basic principles."

When asked to name her "dream" passenger, one who might stand out in the glittering crowd, Warnke mentions actor Paul Newman. "Oh, I've never driven him, and don't get me wrong -- it wouldn't be because of the blue eyes or the Newman image. No, not that at all. I'd want HIM to chauffeur ME around town. Now, that would be a fantasy."