There's one issue that makes PIT maneuver unreliable even with reworked handlings : player synch, and this server isn't alone in having to deal with this issue.
A few years ago we increased Crown Vic's weight in line with that of a larger van to more easily allow PIT manuevers, but for balancing reasons we didn't apply it to the rest of the police vehicles.
I think this is a bit of a trivial issue as usually you would play with squads so I don't know if anything really needs changing here, but an easier solution (not saying it's balanced) would be allowing cops to use small firearms from driver's side