You better study up on the Israelli missile tech, MT. Ny understanding is that they are capable of and do pinpoint the very spot from which the enemy missile was fired from and if so, that spot had to be the convoy. Correct me if I'm mistaken. I will be off to church tomorrow (Sabbath) and Lord willing able to do more responding tomorrow PM.
Buz, as someone who has at times made it a bit of a hobby to study military hardware I can tell that mangytiger is 100% correct.
Those older russian ballistic rockets just can't be fired on the move. They take a decent amount of time to set up and can only be fired from a stationary position.
The katayusha is an old design...... I believe it was originally used (at least in some form) in WW2