Possible Clues:

• Convenience of some gas stations
• Gas station part, often
• Mercantile establishment
• "Who Needs the Kwik-E-___?" (song from "The Simpsons")
• Shopping locale
• K-___ (retailer)
• Shopping emporium
• Mini-___ (store at a gas station)
• Feature of many a gas station nowadays
• Small shopping store