Before leaving
Put shared items in one visible bag: water, snacks, first-aid pouch, charging cables, and a small towel.
Shared car items
Keep the cable roll, snack box, and notebook within reach so nobody has to unpack the trunk during a stop.
Personal small items
Use a packing cube or pouch for layers, socks, and anything that should not mix with food or wet gear.
Bad weather extras
Add a rain poncho, dry bag, and microfiber towel when the forecast is uncertain.
After-trip cleanup
Separate damp items as soon as you get home and repack the shared pouch before the next trip.