I'm aware that cars nowadays are much safer than cars from 20 years ago. And a lot of that progress has to do with design (crumple zones, anti-roll, etc) and airbags.
It seems a bit wasteful to me to discard my old Subaru Forester which works just fine - but I have concerns about the safety of it were I in an accident.
Is there any way to significantly improve the safety of an old car?
All jokes aside, buy the best road tyres and brake pads (inc. discs) that is most suitable for your common driving environment.
Down here in rural Ireland I’ve got “wet / rain” tyres. Not only can I stop on a penny, the car (Audi TT mk1) can also shift pretty quick for safely manoeuvring hazards. 99% of time I drive like a grandpa :-)
Be hyper aware of drivers around you too. If there’s a driver following who clearly shows they are _determined_ to overtake then the safest option is to pull over and let them. Their sense of judgement might be poor and result in a collision where you are collateral damage.