Locking keys inside a vehicle is common. Use a magnetic key-holder to store a spare someplace on the vehicle body or frame. If you don’t have an extra set, many towing companies have tools to unlock your door without damaging the window or paint. Some locksmiths also specialize in this service. If you have a service like OnStar, you can call the toll free number and a representative will send a cellular signal to your vehicle’s computer module to unlock the doors. If your vehicle’s battery is dead and the keys are locked inside, the car doors will not unlock with the remote signal from OnStar. Do not break a window to get inside the vehicle. Commonly it only takes minutes for an experienced tow driver or locksmith to enter a vehicle.