This is a common mechanic in SAMP where you should overtake the car and shoot in the empty space towards the direction where the car goes so the damages are registered on the screen of the damage recipient.
I know I'm not an admin nor a moderator to reply here, but how long have you been playing SAMP?
UPD: Watch a similar video of mine, it's not about shooting though, but about lag pits:
i=jadWcK3m89PM4YH7
