Your right regarding the 2 second rule mate. 2 seconds is actually MUCH more distance than people think. Most just say one two and think thats 2 seconds, but to actually do it properly you have to go.....0 elephant 1 elephant 2

At 70mph thats a hell of a distance, and i agree with burnzy, that if you did actually leave that much room, you would get someone jump in the gap straight away (usually by undertaking you im sure )

More important than the 2 second rule is to look 3 or 4 cars infront of you, so you can anticipate hazards quicker and easier.