Possible Clues:

• Playing for time
• Smart to keep everyone checking
• Prevarication unlikely in serenade
• It's smart concealing everything, using delaying tactics
• Deliberately delaying an event or action
• Smart, concealing everything and playing for time
• If it's high in the inside, it's enough to have the engine stopped (8)
• Everyone involved in swindle is evasive
• Give voice about almost incredible prevaricating