If this isn’t the gadget to give that Geek that has everything, I don’t know what is. From the Aussies, it allows you to open your car door by knocking in the correct code on the car’s window. “Knock-In-Key is the World’s First Back-up Entry Key for your car that requires no external devices, keys or RF signal emitters. Made in Germany and very secure, all you need to do is KNOCK ON THE WINDOW or panel with your own code to unlock your vehicle. Designed for when you lock your keys inside the car or lose them altogether. Very secure and easy to install. Connects to your car’s central locking or just ask your installer about fitting a single door opener if you don’t have central locking and want to keep the cost down.” Check it out for yourself.