[Awide]

Код:

public OnPlayerWeaponShot(playerid, weaponid, hittype, hitid, Float:fX, Float:fY, Float:fZ)
{
	if(hittype == 2)
        {
		new bool: isany_incar = false;

		for(new i = 0; i < MAX_PLAYERS; ++i)
		{
			if(IsPlayerInVehicle(i, hitid))
			{
				isany_incar = true;
				break;
			}
		}

		if(isany_incar != true)//You hit a vehicle with noone sitting inside.
		{
                        //the vehicle's ID you've hit is hitid
			new Float:vHealth;
			GetVehicleHealth(hitid, vHealth);
			SetVehicleHealth(hitid, vHhealth - 50);
		}
    }
    return 1;
}

I hope this helps. If you need more details or an explanation somewhere just tell me, should be clear as you read the code with the comments.