A thin, titanium plate the eaxct same size and shape as your vehicle's windows which sits inside the (slightly modified) door alongside the window in the closed position. If someone points a weapon at your window or reaches in the window to grab you, simply flip a red-capped emergency toggle switch and the shield slams upward in the blink of an eye, eiher trapping/breaking/severing the would-be criminal's weapon/limb, or at least buying you time to shift into drive and put the pedal to the metal.-- 21 Quest, Aug 27 2013 Legal Anti-carjack flamethrower http://news.bbc.co....d/africa/232777.stmBBC news article from 1998 [Tulaine, Aug 27 2013] Go by train?-- not_morrison_rm, Aug 27 2013 Why titanium? Sure, it's a sexy metal, but weight is not really a concern and there's tougher knife edge metals available.
I also wonder if severing or pinching the limb would not cause the trigger finger to spasm, working against your desires.
Lastly, goodbye to your upholstery.
Other than that, it's a great idea.-- normzone, Aug 27 2013 What about a portable device that can be kept on your person or in your glovebox, with a small lever that you can pull to rapidly eject a solid metal projectile towards your assailant? This would have the advantage of being useable on somebody who is already in the vehicle.-- ytk, Aug 27 2013 Can I suggest a much simpler alternative?
All that is needed is a noose of cheesewire set into a channel in the rubber seal of the window, and a pneumatic device in the door body which, when triggered, draws the cheesewire out of its channel and downwards.
Admittedly, the cheesewire idea is somewhat more elegant than the idea of a titanium plate, but on the other hand the cheesewire is likely to be simpler to install in a normal car.-- MaxwellBuchanan, Aug 27 2013 If you're not worried about breaking or severing limbs, then a cheaper and much less intrusive solution may be the South African notion of a flame thrower mounted beneath the car and controlled by a pedal in the driver's foot well to blast flaming gas at would-be car jackers. Despite concerns raised by do-gooders this was declared legal by the authorities. (See link)
Seems it never caught on outside South Africa though.-- Tulaine, Aug 27 2013 //Police say they cannot see any legal problems with the blaster - so long as the right people are blasted//
Don't you just love these third-world countries for their wacky humour? SA, TSA, USA... all the SAs.-- MaxwellBuchanan, Aug 27 2013 Weight of materials is always a concern with vehicles, for a variety of reasons. The device is called a shield instead of a blade because cutting/entrapment is a secondary objective: the primary objective is to place a bulletproof barrier in the window at the flick of a switch.-- 21 Quest, Aug 27 2013 random, halfbakery