You need to report this to the police. Just give them a quick call on 101/call the switchboard and say that you had a couple of dodgy guys looking into your car last night at 1am and you've got some CCTV if anyone wants it. It'll be logged and could be potentially good information.
For all you know, they may have done a smash and grab on a car 200m down the road. Even if they didn't, this kind of stuff can be invaluable. If they broke into a car tomorrow and stole something and got caught, tried to claim it was just a moment of madness and they've never done anything like this before, to get a reduced sentence, and the Police produce a video of them the previous night going around looking into cars, it's going to blow their mitigation out of the water.