But I don't think either of those things is true. Would you support Israel blowing up a car on a crowded New York City street if this man was the target?
This was a PFLP commander, and his untimely death occurred just a day after a PFLP bombing in Netanya.
If you're trying to send a message, you want to:
a) kill somebody important, to give the other important guys pause the next time they think about trying it.
b) make it very public, so that there can be no mistake that he was taken out.
c) use a bomb. For one thing, direct assassination means that your people might be caught and/or killed. But more importantly, the ability to place a bomb in a commander's car is guaranteed to make them shaky about their security, and thus puts them off their game.
This is an ugly game, but it's very important to be able to play it well.
Maybe in Newark. That way, nobody would notice.