"...My cousin said that he bought and sold many cars..."
Oh, I see. Please find below information about ambulances, most if not all based on Buicks, furnished with a "cracked ice" system. I've turned the main articles into PDF-files (attached) to make them better readable.
sources #1 - 1938-10-11 The Inquirer, Owensboro #2 - 1938-09-06 The Sun, Baltimore #2 - 1938-06-19 The Sedalia Democrat And Capital #3 - 1938-06-20 The Inquirer Owensboro #4 - 1938-06-19 The Sedalia Democrat And Capital #5 - 1938-10-15 Indiana Evening Gazette #6 - 1938-06-20 The Inquirer Owensboro #7 - 1938-10-15 Indiana Evening Gazette Click to enlarge!