My parents had seat restraints when we were younger from Mothercare, bolted into the car so we were buckled in long before it was a requirement. But then later, I remember DF taking the whole team from our gymnastics club to a competition in the city 25 miles away and squeezing 12 kids into the (estate) car - I would have been about 10/11 at that stage.
My DPs were from the city, but we lived in the country (and DF had a professional office-based job) - I used to go farming with a local family, hitching rides on the tractors (and occasionally having some involvement in operating machinery) from about age 6/7. Just disappearing for hours and coming home to eat.
Also going to a local spot where a drainage ditch (small stream) fed into a large pool, scrambling around the trees there, and just generally hanging out in peace and quiet alone (large, chaotic family!).
Bird watching from the boot of a (no longer in use) car, with the boot lid pulled down low propped up on a stick to make a "hide".
Going swimming alone at 5am in summer time (safe spot, with passing traffic at that hour - but still...).
DPs used to not allow us to hitch a lift - so I would walk home 4/5 miles from one local spot along very quiet roads after dark. Which was worse I wonder?!
Use DFs tools in the garage. Cutting the grass with the petrol mower from age 11 or so (and younger DSiblings started earlier - as eldest, I had to pave the way and argue for many moons!!). And the large chopper axe to cut large tree rings into firewood sized logs (I had a pair of steel toe capped boots, but I could take some swing at that axe to get rid of the frustrations of the chaotic household!! Admittedly I was the only one who did the axe).
Playing on various building sites over the years, clambering up ladders in the evenings when builders were gone home etc.