Re: Not a lot of people know this ..
So you shake your head, back of the throttle a little bit and let the gap grow again. It's not hard. (And no, this doesn't mean "you can't move at all because people keep diving into the gap". In reality most people on the road aren't total bellends despite what it feels like.)
Btw, at 30kph, 2 second rule means you should be keeping about 16 meters distance. Which is more than 2 car lengths. (2 car lengths is almost never enough!)