1) It's possible there are traffic cameras covering wherever they get into the vehicle.

2) It can be used in conjunction with other assets watching who got in etc...

It's also possible that they simply went ahead and hit the vehicle, knowing there was a good chance that their target would be inside. It's not like they've been all that picky about collateral damage.

Why risk starting a war and not be 100% confident where the leader is?

Risk starting a war !!

That was the whole freaking point.

The attacking forces doesn't give a flying F about Iranians otherwise the sanctions would have been removed long ago on humanitarian reasons.

Most wars are started without targeting the leader at all.