Rolling through the streets of Los Angeles in his 1941 Tatra T87, Mr. Paul Greenstein might as well be invisible. Other drivers speed past his Czech oddity without a second glance, seemingly oblivious to the car's dorsal fin and triple headlights. But as Paul swings the Tatra into a parking space in front of a favorite local bistro, it's as if he has brought the black teardrop to a stop in the middle of a Hollywood spotlight that immediately attracts the attention of every passerby. Here come the second glances, the puzzled questions. "What in the world is that?" "Is that a...a Citroen? A Volkswagen? An, uh....I mean, what is it?"