Possible Clues:

• Fast-food chain whose slogan was once 'If it doesn't get all over the place, it doesn't belong in your face'
• Fast-food chain with Famous Star burgers
• Home of the "All-Natural Burger"
• Home of the 'All-Natural Burger'
• Thickburger seller
• Fast-food chain with a smiling star in its logo
• West Coast burger chain
• Hardee's equivalent, out west
• West Coast burger chain advertised by a writhing Paris Hilton washing a car