spat

A spat is a separate panel of bodywork bolted or riveted to the outer face of the rear fender, extending from the top edge of the wheel well down and around the upper third of the tire. Its sole function is aerodynamic and aesthetic: to smooth the airflow over the rear wheel and eliminate the visual bulk of an exposed tire and suspension assembly. The spat forms a streamlined surface that continues the car's side profile without interruption.

Spats became common on higher-end vehicles in the 1930s and 1940s, when aerodynamic theory began to influence passenger car design. They remained a styling marker of more formal or luxury automobiles through the 1950s and 1960s. Unlike a full fender skirt, which encloses the wheel almost entirely and reduces ground clearance, a spat leaves the lower wheel and tire visible and does not interfere with tire access or suspension service.

Materials and Construction

Traditional spats were formed from steel sheet and painted to match the body color. Modern examples use fiberglass, plastic composite, or aluminum, which reduces weight and simplifies replacement. The panel is typically attached using self-tapping screws, bolts through pre-drilled holes, or adhesive bonding to avoid altering the parent panel. On some designs the spat wraps partially around the rear quarter panel as well, creating a continuous aerodynamic line from door to wheel.

The main design challenge is the gap between the spat and the fender, which must be sealed or disguised to avoid a sloppy appearance. Poor sealing also allows water and road spray to accumulate behind the spat, promoting corrosion on the parent fender. Drainage holes must be provided on the underside to prevent pooling.

Spats fell from favor after the 1970s as aerodynamic gains became marginal and maintenance costs rose. Modern vehicles with integrated aerodynamic body sculpting have largely eliminated the detachable spat, incorporating its function into the main fender form. They remain occasional styling details on retro-inspired vehicles and some luxury sports cars where visual continuity and smooth surfaces are prized over mechanical simplicity.