The Norwalk motor car, made in Martinsburg from 1912 to 1922, was West Virginia's most successful attempt at automobile manufacturing. The car was named for Norwalk, Ohio, where production had begun in 1910. After financial difficulties in Ohio, the operation was moved to Martinsburg, where local investors were recruited.

The flagship vehicle of the Norwalk Motor Car Company was the Norwalk Underslung Six, a huge car by modern standards. It featured a 500-cubic-inch, inline six-cylinder, 8.6 liter engine; by comparison, a 350-cubic-inch, 5.7 liter V8 is considered a large engine early in the 21st century. The wheelbase of the Underslung Six was 136 inches, more than 20 inches longer than a full-sized 2004 Cadillac, and the big wheels stood 40 inches tall. The car, a convertible, came in different versions, including two-passenger and three-passenger roadsters and a six-passenger touring car. The touring car sold for $3,100, several times the price of a Ford Model T.

Financial difficulties continued to trouble the company, and few of the big Underslungs were built after 1915. Norwalk instead manufactured smaller four-cylinder cars as well as trucks. Two Norwalk fire trucks were put into use by Martinsburg firefighters. The company closed in 1922. The big factory, later used by Interwoven Mills, burned in 1989.

There were several other attempts to manufacture automobiles in West Virginia in the early 20th century, including the Remington of Charleston, the Jarvis-Huntington and the Enslow of Huntington, and others. None lasted as long or produced as many cars as the Norwalk Motor Car Company. Late in the century West Virginia developed a thriving business in the manufacture of auto parts and components, including the Toyota engine and transmission plant in Putnam County, NGK Sparkplugs of Kanawha County, a major stamping plant in South Charleston, and other operations. No automobiles have been assembled here in recent decades, although Hino Motors began building medium-duty trucks in Williamstown in 2007 and moved to a larger plant at Mineral Wells in 2019.