We may be able to take few precautions against booby-trapped cars but there’s nothing we can do when it comes to suicide bombers. One thing that caught my attention though is that it seems as if the car got passed a security checkpoint on its way. If the Lebanese Army or ISF don’t have the proper tools to detect explosives, a good idea would be to have some kind of reader that verifies the plate number and tells if the car is stolen or not. Whether the plate number is fake or the car is stolen, matching it against some secure online database would do the trick. In fact, I wouldn’t be too worried about making that list public since all medias have access to it (don’t know me how) and don’t hesitate in posting who the car belongs to few minutes after every explosion.
Of course that’s not the ideal solution for preventing bombings but it would help detect stolen cars and cut down the chances of a potential attack.