Starting with the ‘36 Cord and ending only in 2004, when the Corvette was last produced with pop-up lights, this feature allowed for smooth, aerodynamic front ends and kept the lights clean when retracted. Of course, it added complexity and weight, needing motors or linkages to raise and lower the lights. In the 1960s, some cars were “required” to have them in order to meet US minimum-height laws for headlights. A majority of the reason that these lights have become less common is that European pedestrian safety regulations have rightly pegged a popped-up headlight as a hazard, and thus manufacturers have shied away from using them.