The Daytona was a Speedmaster knock-off. Speedy debuts in '57 with the first tachymeter on the bezel, being practical for drag racing and car racing. When the 5 year patent (external part) expired, Rolex launched the Daytona (car race) and Heuer launched the Carrera (also a car race). All hand manual-wind movements. Rolex almost couldn't give them away until '88 when the El Primero became the engine. Suddenly it took off.
The AmVox2 series, although not the first automatic chrono by 40+ years, was the first real departure from chrono activation, and still - to this day - is IMO the coolest, most remarkable chronograph in the world. The DB9 version took it to a completely different level, being able to be tied to a car's security system. (I've long said that JLC should have made a version that could be programmed to any car, and can be re-programmed for your next car, too.)
My favorite of the AmVox2 series was the "concept" version, with ceramic case. Why? because the subdials were more discreet, being read at 3 and 9, and almost hiding the fact that it was a chronograph.
-Dean