A word of caution for you when using that bag. In order to prevent unleashing every single cuss word you know, and even perhaps making up a few new ones, note that the tops only fit into the bag correctly one way. The black side of the top faces in so it sits against the black divider and the short side of the tops go in the bag first. Also, look at the shape of the bag and notice one side is straight and the other side curves. Be sure to orient your top accordingly before trying to put it in the bag.
Done correctly, it isn't a bad task at all and can be done in no time. But get it wrong and prepare for spiking blood pressure. Also, the bag is designed to be taken with you in the back. The strap on it goes around the back seat headrest, holding it firmly in place. Unbuckle the strap, run both ends around the headrest and re-snap. You want it to fit snug so they don't flop around back there while driving so adjust the strap if necessary.