The base model initially had the 1984-87 front fascia with exposed sealed beam headlamps.

Vehicle designs in the 1970s frequently included metal bumpers with simple replacement of sealed beam headlamps.

The limited range of standardized sealed beam headlamp sizes and shapes restricted styling options for automobiles.

The outer pair of the quad, five inch, sealed beam headlamps were twin filament, giving the car four main beams.

Sealed beam headlamps were introduced in the United States in 1939, and became mandatory from the following year until the 1984 model year.

Sealed beam headlamps are modular; when the filament burns out, the entire sealed beam is replaced.

These were effectively prohibited in the US, where standard-size sealed beam headlamps were mandatory and intensity regulations were low.

The sealed beam headlamp was introduced in 1936 and standardised as the only acceptable type in the USA in 1940.

The Citroën DS shown here illustrates the large differences in headlamps during the 1940-1983 era when US regulations required sealed beam headlamps.

At the same time, the headlamps were changed from the original incandescent light bulbs to sealed beam headlamps, and the original steel doors were replaced with new stainless steel doors.

The headlights (the example illustrated has been converted to '40 Ford sealed beam headlamps - '39s used bulb and reflector lamps, the last year for these) were moved farther apart, now sitting almost in front of the wheels.

Due to the American sealed beam headlamp requirement in place at the time the USA models had a special front fascia with four round headlights instead of the two rectangular units it had in other markets.

The unique front end featured an offset hood intake duct for the turbo intercooler and a grill-less nose with sunken single rectangular sealed beam headlamps, flush inboard parking lamps and wraparound outer turn signal lamps.

The actual operating voltage may differ from the nominal rated voltage; for example, "12 volt" sealed beam headlamps are meant for use in automobiles with typical line voltage of 13.5 to 14.2 with the engine running.

Halogen sealed beam headlamps appeared on U.S. cars in 1978 to enable halogen technology under Federal Motor Vehicle Safety Standard 108, which at the time required all headlamps to be of sealed beam construction; eventually halogen sealed beams came to dominate the sealed beam lamp market.