There are lots of checks to make and work you might want to have done to a newly purchased used car. It's best to consult a buyers guide for the make and model you're interested in order to avoid common problems. But regardless of specifically what a car might need there are a few things you can do to any car that will help to improve the experience of owning and getting to know the vehicle.
1. Battery isolation switch:
This is a cheap way of allowing you to disconnect the battery easily. It's useful for a number of situations including: long term storage, security, maintenance etc. It can also help if you are having alarm or electronic problems by enabling the tried and tested ‘turn it off and on again’ approach. Fitting is as simple as disconnecting the negative battery cable from the terminal and connecting it back up using the clamp on the new isolating switch. Then to open or close the switch all you need to do is turn the knob on top.
2. Headlight cleaning / restoration / upgrades
The better the lights are working, the safer and less tiring driving in the dark will be. Anything from cleaning the lights thoroughly, to sanding and polishing the lenses, to replacing the bulbs or whole unit for brighter ones will help. Try cleaning and restoring them first before upgrading, and if you do go for an upgrade make sure you're operating within the law.
There are plenty of guides and kits to help and you can even try simple things like an abrasive toothpaste and an old toothbrush to bring the lenses back from cloudy to clear.
3. Tyres
Tyres are vitally important and while not cheap a full set of matching tyres can make a huge difference to the handling and safety of a car. Unfortunately both age and wear can affect tyres so if you have more than one tyre which is older or heavily worn consider replacing all of the tyres if your budget can stretch to this. There is a difference between the quality and type of tyres available. This is a huge topic so do some research before you buy but my main point here is please don't put it off!
4. Floor mats
Having no or poorly fitting floor mats which shift about under your feet as you drive can be a big irritation. It is such a simple thing to do. Your old mats needn't be thrown away either and could be recycled or used to lie on if you like to work on your own car. It really makes a difference and there are some great businesses out there offering you the opportunity to customise your car while having something made to the exact template of the floor pan. Avoid cheap universal mats if you can: they are usually a false economy and signal to a potential buyer that you may have maintained a car on a shoestring if you come to sell it.
5. Emergency kit
At a minimum it pays off to have to hand in your car:
Locking wheel nut key (if applicable)
Wheel bolt / trim removal tools (if applicable)
A car jack
Wheel brace
Spare / space saver wheel
High visibility jacket(s)
Tyre pump
Owners hand book / manual
Fuses (many more modern cars come with a few spares somewhere)
Bulbs
Jump leads
A screw driver with assorted bits
A torch (a magnetic one can be very handy).
A cloth or sponge.
In the summer and winter you might add a few things relevant to the weather you're likely to encounter and swap them around if you're short on space.
It is not easy to solve problems working at the side of the road without a full toolkit and spare parts. But the more prepared you are the greater chance you'll have. It also helps to put your mind at rest even if you never break down that you have made some provision for it.
All this said there is no shame in calling a breakdown specialist if you need to. They will have seen the same problems numerous times and tend to have a lot of tricks to get you back on the road, but crucially whatever happens you won't be left stranded. So while you're at it make sure you have your breakdown number to hand.
In conclusion
If you're a car enthusiast like myself you might be prone to obsess about things most motorists wouldn't even notice or really worry about. But assuming you have the basic servicing and an MOT sorted out there are a few simple steps like those I've suggested you can take which make ownership of a vehicle more pleasant.