You will grow to love your wagon more and more if you are like most of us, congrats!
I like that Pikibu mirror and will get one, I initially looked to get something like that but only found poor quality ones.
Ours is a low roof and we get around in it okay, but we're short. We like fitting in parking garages.
Mine has the charcoal seats too, they look so much nicer than the pale grey ones. The deciding factor for us were all the stained pewter seats in the used rentals we looked at. With 4 kids in car seats, you'll be glad for that.
The limited LATCH points is annoying to me too, we put up to 3 seats in for the grandsons and I would appreciate more options.
I am so glad I replaced the factory step with the Ionic ones, you won't be disappointed.
Besides tinting the front windows, I added a tint strip across the windshield, it helps a bit.
I keep a medium size black wastebasket in the back, those kids can generate some trash! The key is finding one without a skinny base that won't tip easy.
I have 3 keypads on our wagon, SO convenient!
We usually have the right rear seat removed and the left rear in its place, which makes moving around from front to back for all the stuff convenient, plus a little extra floor space. When we need all 12 seats, I put it back in. We have 2 black storage bins
back there for odds and ends.