My car is a hot mess. It only has one seat pocket behind the passenger seat so stuff ends up in a pile on the backseat floor

Here is the stuff I "need" to keep in my car:
- a blanket for each kid
- one or two small toys for each kid
- sunscreen
- my SSC
- activity book for DD
- diaper clutch
- wet bag with a change of clothes
- wipes
- hand sanitizer
- a couple of snacks just in case
- water bottle for each kid plus me

Anyone have any tips or specific organizers that would work? We'll be three across later this year so it will only get worse...