Is that true?
C.W. McCall is a fictional character.
From Wiki:
In 1973, while working as a creative director for Bozell & Jacobs, an Omaha, Nebraska advertising agency, Fries created a Clio Award-winning [1974] television advertising campaign for the Metz Baking Company. The ads featured a truck driver named C.W. McCall, who was played by Dallas, Texas actor Jim Finlayson. The commercial’s success led to songs such as “Old Home Filler-Up an’ Keep on a-Truckin’ Café,” “Wolf Creek Pass,” and “Black Bear Road.” Fries sang and wrote the lyrics, and Chip Davis, later of Mannheim Steamroller, wrote the music.
Mannheim Steamroller actually began as an alias for record producer/composer Chip Davis. The name “Mannheim Steamroller” comes from an 18th-century German musical technique, Mannheim rocket or roller, an ascending arpeggio popularized by the Mannheim school of composition. Before the fame of Steamroller, Davis had been best known for creating the country music character “C. W. McCall” (of “Convoy” fame) for his friend Bill Fries. Even before Davis made McCall a star, he produced an unusual album of classical music performed entirely by Davis and musical collaborator and keyboardist Jackson Berkey, using electric bass (played by Eric Hansen) and synthesizers. Since no major label would handle its distribution, Davis founded his own music label, American Gramaphone (a play on the classical record label Deutsche Grammophon), to release the album. The result, Fresh Aire, was released in 1975 under the pseudonym Mannheim Steamroller, in the hopes of the album being a best seller. Fresh Aire II was subsequently released in 1977 and Fresh Aire III was released in 1979. The first four Fresh Aire albums constituted a “four seasons” exploration, with Fresh Aire being spring, Fresh Aire II being fall (less obviously than the others), Fresh Aire III being summer, and Fresh Aire IV being winter. All four of these albums maintained the blend of baroque classical music, light jazz, and a light sense of humor (Davis is credited as playing “more toys” on the Fresh Aire III album credits), and featuring Jackson Berkey’s virtuosic keyboard work (for more examples, listen to Berkey’s own Sunken Cathedral for master performances of classical works by Debussy, Persichetti and others). Davis and Berkey would use whatever instrument seemed appropriate to the piece, using toy piano on one piece and full pipe organ on another, with copious interleaving of piano and harpsichord. Davis then moved into exploring some other themes, with Fresh Aire V being subtitled “To the Moon,” Fresh Aire VI exploring Greek mythology, Fresh Aire 7 being based on the number 7, and Fresh Aire 8 being based on the theme of infinity. A live tour of the early albums featured a prominent light show and multimedia components, along with spoken poetry by Almeda Berkey. While the music was slightly different from the album versions, the music was played in lockstep at each show, as it had to coordinate the live musicians with recorded tracks of strings and other orchestral parts.