"I'll waste more gas turning off my car and then turning it on again instead of leaving my car to idle."
FALSE: You don't expend more gasoline turning your car on than you would idling. This is simply not true. (10 seconds of idling wastes more fuel than restarting.)
"Idling is good for my engine."
FALSE: It actually gums up your engine making it operate less efficiently when idling. Driving is the best thing to do for your vehicle because it moves fluids through the engine. Turning your car off is better for the engine than leaving it running when not in motion.
"It's bad for my starter to keep turning it on and off."
FALSE: You will not wear out the starter turning it on and off. Many cars do this automatically when not moving.
"It will take a long time to warm up the engine if I turn it off."
FALSE: Actually, after 30 seconds your engine is hot. Even in cold weather, engines warm up faster when moving than sitting still.
"It will damage my starter if I keep turning it on and off."
FALSE: Modern cars are designed to handle multiple restarts throughout a day and won't hurt it at all. Many cars even include options to have your car automatically shut off rather than idle. Since electric ignition became universal in the 80s, restarting your vehicle does not result in significant fuel loss.