Possible Clues:

• Automotive inits.
• Model M car of the 1910's
• Flying Cloud, e.g.
• Locomobile contemporary
• ''America's longest-lasting car''
• Car once called 'The Gold Standard of Values'
• Auto of long ago
• Old autodom's Model M or Model T-6
• Royale, of 30's autodom
• '20s-'30s Flying Cloud, e.g.