I got the car starter kit from Woot a while back. We've hardly been able to use any of it:
--The mirror: clip doesn't have enough capacity for the fold-down visors in our Honda Fit. Even if we make it kind of pinch enough to stay, the mirror vibrates so much on its long stem that we can't really see the baby anyway, and it has to be removed for the visor to flip up. Our windshield has a glare-reduction pattern at the top of the windshield between the two visors, which prevents the suction cup from sticking. Complete fail.
--The back-of-seat organizer hangs away from the seat so loosely that it takes up most of the legroom in the back seat, both for an adult and for my daughter in her carseat. Even so, she couldn't reach items in it while strapped in her carseat. Might be better on seats on which the back is actually completely vertical (minivan?) or hanging on the back of a door, side of a changing table, etc.
--Commenters on the previous Woot said that the car seat mat was contraindicated for the safety of some car seats, although I don't see why it would make a difference with LATCH connectors and proper installation. I was going to try it next time we had to move the carseat anyway, but then decided to repurpose it as a picnic table mat for camping.
--The window clings do ok in our car. We can roll the windows down and back up without removing them.
--"Little Explorer" sign? Ok, if you like that sort of thing.