Since this is more or less Britain, I'd vote for the Challenger 2 MBT
It will simply roll over any "normal" automobile, leaving behind a trail of flattened Jags, Bentleys, Land Rovers, Beamers and Morris Minors.
EDIT - And the very occasional Reliant Robin.
EDIT2 - And if "quickly" takes precedence over "safely", the Mythbusters episode suggests that the rocket-powered Robin Reliant Robin should be considered.