Possible Clues:

• Vehicle to break down in plant
• ____ and stick
• Barrow runs round inside plant
• Vehicle to decay in plant
• Incentive to get back into motor racing
• Incentive to cover up conductor? Rachmaninoff!
• Incentive for panel game host to do send-up
• Part of some frozen faces
• Sign of something extra, or amount of gold, announced as incentive
• Metaphorical tempter