Possible Clues:

• "Let __!": "Go ahead!"
• "Let __!": "Get going!"
• “Let ___!” (“Go ahead!”)
• 'Let ___!' ('Go ahead')
• See 27-Across
• 'Let ___!' ('Full speed ahead!')
• "Let __!": "Start the ball rolling!"
• Car gadget for iPods
• 'Let ___!' ('Set 'er loose!')
• FM accessory for Apple players