The car is, as noted, a 1962 Abarth Simca 1300. The significance of the single driving light is that this apparently was a requirement to compete in the 24hrs of LeMans. The car was campaigned by Claude Dubois and Georges Harris at LeMans in 1962. It was the only Abarth Simca to finish the race and finished 14th overall. More importantly, it finished 1st in its class (1300cc experimental). The results aren't quite so stunning when you consider only 18 of 55 cars finished the race, but just finishing is an accomplishment.
Here is a shot of the business end...