One of the ways you can save major money on car insurance is by opting for a plug-in diagnostic kit. Known as SmartRide, Snapshot or In-Drive (depending on your insurance company), this device attaches to the inside of your car (like an external hard drive connects to a USB port) and gives you personalized feedback to help you make safer driving decisions. All of your actions while behind the wheel -- miles driven, speed, acceleration, deceleration, what time of day you drive and how quickly...