Pre-production car

[6] Chevrolet built 43 pre-production, third-generation Corvettes, but none were released to the public as the automaker skipped over the 1983 model year and decided to introduce the new cars as 1984s with an extended production run.

In the case of American Motors (AMC), these included appearance modifications such as grilles, tail lights, trims, or interiors that were fabricated in clay, fiberglass, wood, or plaster.

Designs were tested in these cars in response to customers and drive reports, as well as to include better solutions like making the ashtray and cigar lighter more user friendly.

[10] Automakers put new technologies in endurance or motor sport contests to test their use in extreme conditions before incorporating them in production cars.

[14] Major safety improvements may be taken into account during the initial development stages of vehicles, but not removed from actual production cars even after the proposed stiffer regulations are rolled back.

[15] The AMC Pacer was designed with shortened ends, but incorporated "new impact energy absorbing ideas" to perform at higher crash speeds than the final U.S. regulations that were mandated for the 1975 model year production.