Never had an issue following comprehensive planning and optimising of in-car resources! I can't think of anything else I'd have that couldn't be chucked behind a seat or in the boot for the trip
Phone: mounted
Wallet: slimmed down to 6 cards in card holder with folded cash. Easy in any front pocket even for a fatty in slim jeans.
Ray bans: front of drivers door pocket
Extra Keys: change holder
Change: ashtray
Pocket sized tissues: rear of door pocket
Tissue box: behind passenger seat
Charging cables: integrated to hidden socket, passenger's end in net.
Water bottle: tucked next to seat. Definitely not in cupholders, which shall never be opened in my ownership
Temporary items: (e.g. parking ticket) - under handbrake
Glove box: Insurance and breakdown info; Hand sanitiser; pack of face masks; sun cream (100ml); back up driving glasses; emergency fruit mentos
Centre storage: Leatherman; OBD code reader; interior wipes, sound generator foam. Still full of CD and Nav units to be removed
Boot corner: Halford professional mini socket set, tyre gunk and pump
Other corner: Emergency microfibre towel
Random garage purchases: passenger seat, footwell or wife.
Passenger's stuff: their problem