Write this in public OnPlayerDeath.
[pawn]if ( reason == 39 )
{
format( string, 128, "Auto-Kill:[ %s ] Reason:[ Vehicle-Kill ]", gPlayers[ killerid ] );
SendClientMessageToAll( COLOR_GREEN, string );
SetPlayerHealth( killerid , 0);
RemovePlayerFromVehicle( killerid );
}[/pawn]