I've just spent far too long testing all weapons drive-by (driver and passenger where applicable) and buffed pretty much all weapons. I agree they were very bad before. The problem arises when there are 4 players drive-bying from a vehicle against someone, it's almost instant death for the victim, but I suppose that would be the same on-foot, it's just they can ambush you without warning leaving you fucked.
I have also re-enabled 'far' damage. For some reason currently damage ranges are close (<20m) or medium (20m-200m). I'm not sure why 'long' range is disabled, but I'll make 'close' range 15m and medium range 50m, and long range 50-200m.
But yeah, here are the relevant new damage values (hp) for (left to right) close range [< 15m], medium range [15-50m], far range [50-200m], driver DB [up to 200m] and passenger DB [up to 200m]:
{ 11.0, 7.0, 2.0, 0.0, 4.0 }, // Colt 45 (9mm)
{ 10.0, 6.0, 1.0, 0.0, 4.0 }, // Silenced 9mm
{ 35.0, 24.0, 15.0, 0.0, 8.0 }, // Desert Eagle
{ 40.0, 18.0, 1.0, 0.0, 19.0 }, // Shotgun
{ 18.0, 10.0, 1.0, 0.0, 10.0 }, // Sawn-off
{ 24.0, 16.0, 1.0, 0.0, 8.0 }, // Combat Shotgun
{ 4.0, 3.0, 1.0, 1.5, 7.0 }, // Uzi
{ 6.0, 4.0, 2.0, 2.0, 8.0 }, // MP5
{ 10.0, 6.0, 3.0, 0.0, 6.0 }, // AK-47
{ 8.0, 6.0, 4.0, 0.0, 7.0 }, // M4
{ 4.0, 3.0, 2.0, 1.5, 7.0 }, // Tec-9