Related Clues:

• 21-Across, e.g.
• Prefix with mate or graph
• Means of transport
• Truck compartment
• Rail runner
• It can be in a jam
• Showroom display
• Self-starter?
• It's tired, really
• Mobile leader
• Type of insurance
• Jaguar, for one
• Aurora or Saturn
• Prefix with "graph"
• Popular rental