Glad you got away cleanly mate, sharp thinking and well deployed clearance.
It does make your heart sink when you think that could've been your partner/wife with the children.
As Andrew said, I've learnt that the 'tyres on tarmac' rule is invaluable, leaving a car lengths gap to the vehicle in front. Gives you that breathing space to either dive for the opposing lane (if safe to do so) or clamber up the kerb/verge or whatever it may be to get to safety or to escape. Space and time is always a bonus in those situations.
It's even unluckier if you were just passing through Liverpool. Proper opportunists
Not like they'd seen your Mk5 and had been scoping it out for a period of time.
I hope your police friend see's them through the scope of his MP5 soon!