Supposedly, Patrick McGoohan picked the Lotus Seven because it had a more rebellious quality about it that fit the premise of The Prisoner. If McGoohan had chosen the original Lotus Elan he had planned, or some other car for the title sequence, there might not be over 160 companies offering replicas and Seven-type cars over the years. Who knows, we might not even have the Ariel Atom, which is clearly Lotus-inspired. He put the Seven on the map.
The Lotus Seven was an interesting car. It had fantastic low end acceleration for the time, since it was so light (a bit over 1100 pounds), but only had a top speed of around 90 mph. As time went on, the weight and engine size increased, culminating in the Super Seven which had a 1.7 liter engine.
It didn’t make much of an impact on the racing circuit, but it was a fun to drive, interesting car that had a big impact aesthetically on the auto industry.