Walking stick, blue badge, charging cables plus power pack, sunglasses, spare bulbs, jump leads, tyre compressor, wheel brace, bottle jack, locking wheel nut key, hi-viz jacket, walking stick, folding stool, umbrella, folding poncho, fleece jacket, torch, spare batteries (all in case I break down, as I’m disabled and cannot stand at the side of a motorway for hours!).
Fire extinguisher/blanket, first aid kit, bottled water, small gas stove, kettle, tea/coffee/sugar/powdered milk, salt/pepper, mug/plate/bowl/cutlery set, ridge monkey pan, tissues, toilet roll, baby wipes, toothbrush/toothpaste, hairbrush, scrunchie, sun cream, deodorant, hand sanitizer (I’m a regular camper - my car is actually a micro camper van - so all this stuff tends to stay in permanently in a box, as well as my folding bed/bedding, portaloo and window blinds. Handy in all sorts of emergencies though!).
Also currently - dog crate, non-perishable food (couscous, beans, pasta, tuna etc), pop up awning, small folding table, camping chair, change of clothes and about a million bags for life!