Well, let's see...
Whatever vests these guys had, and whatever they'd been smoking was enough to allow them to shrug off 70 direct 9mm hits... The 92FS is by no means an innacurate gun, but if they got hit that many times, a few more won't make a difference... As for head shots vs a moving target that's firing back at you with an AK, not likely...
Also, there's nothing in your average police crusier that will stop 7.62x39 FMJ, except MAYBE the engine block. However, if the block absorbs any fire, your chances of successfully impacting the target are greatly reduced, and you become a sitting duck... Plus, there's plenty of area not protected by the motor... Not much chance for surviving an attempt to ram (although you would draw alot of fire... A charging car is quite loud, obvious, and so on...).
I think fall back and call for backup would fit... Esp if there was a helicopter on hand to follow the BGs from outside the effective range of 2 drugged up wanna-be Rambos who had just watched 'AKs for Dummies, a reference for the rest of us' and deicded to rob a bank...
P.S. Considering the Hollywood depiction of the AK (i.e. it's a 'bad guy gun', easily susceptable to 'Stormtrooper Syndrome' (i.e. extreme inaccuracy)), if these guys really paid attention to their movies, they would have picked different guns... [;)]