Paul Gerding (1895-1983) made a number of very nice illustrations for automobile advertisements, especially in the late 1920s to mid-1930s. He did other work, but I found little of it on Internet searches. Part of my problem is that illustrators did not always sign their work -- usually due to the ad agency or its client's policy.
Because of all that, I could find little more than Gerding's birth/death years. So this post simply focuses on the examples of his work I selected.
The image above is cropped from a 1932 Pierce-Arrow advertisement. Pierce-Arrow was a luxury brand in decline due to the Great Depression and strong competition from the likes of Packard and Cadillac. I think Gerding did a fine job here, especially the lighting and use of color. Media were probably watercolor and gouache.
The advertisement source of the image at the top of this post.
Now for three 1927 Pierce-Arrow ads by Gerding. Here the car is incidental to the people in the foreground.
Gerding painted both the car and the setting. Often a different artist was used for each type of subject because cars are not easy to render convincingly. Perhaps the most famous example is the long-running Pontiac series illustrated by Art Fitzpatrick (cars) and Van Kaufman (setting and people).
Again, people in the foreground, car to the rear.
Another 1932 Pierce-Arrow ad.
And another.
This illustration (not signed, but attributed) is of a 1933 DeSoto.
Ultra-luxury Duesenberg cars for 1935 were advertised using black-and-white illustrations by Gerding featuring seriously wealthy looking people, but no cars in sight.
Around the time of World War 2, Gerding pained a number of scenes for Republic Steel advertisements.