Want to stop someone really, really fast? The new X-Net Car Arrest System will take any car down to a complete stop in a matter of seconds. How, you ask? Easy-peasy. Walk with me.
The X-Net is, unsurprisingly, a net. You toss it out in front of the vehicle you want to bring to a halt, and as it drives over it, spikes embed themselves in the tires. This wraps the netting up in the tires really quickly, forcing the wheels to a stop. Basically, it's like pulling the e-brake from the outside, and there's nothing the driver can do about it.
Of course, you'll be seriously screwing up any car you do this to, so it's not for use as a prank on your mom or anything like that. It seems more designed for law-enforcement types, but I'm sure us civilians can find fun uses for it as well.