Related Clues:

• Auto racer's concern
• Goes 'vroom vroom'
• Races in neutral
• MLK and Ralph Abernathy, for two (Abbr.)
• Makes a car go vroom
• Makes purr, maybe
• Races, in a way
• ___ up (accelerates)
• Goes "vroom"
• Races, like an engine
• Runs engine very swiftly when starting?
• Checks an engine, perhaps