Buy a used car from a Main dealer
You will pay more for the car because they have big overheads.
It should have a main dealer service and they will be able to sort out any issue to your total satisfaction. There should even be a no quibble 30-day return policy and take whatever you have in part exchange. The downside is that because of available space and their insistence on quality stock the used range may not be that used. You will be offered nearly new or fairly expensive two or three year old vehicles. For older cars look elsewhere.
Buy a used cars from a private seller
It is best tp buy from someone who has clearly cherished the car they are selling. Even better if they have a folder full of history and the seller a plausible reason to sell. So the rule is always buy an enthusiast car from a real enthusiast if you can. Private sellers can be expected to look after their cars. They may have the balance of a manufacturer warranty, or an independent one that applies to parts, be it tyres, battery, or alternator. Private sellers can be optimistic about the price. However, there’s no legal comeback against a private seller, provided they haven’t misled you, or sold an unroadworthy car.
Buy a used car from a car supermarket
Lots of cars to choose from which is good, often arranged in related rows to make it even easier for you. Windscreen prices are plus an admin fee and usually non negotiable. However, some cars are direct from company fleets and auctions so can be scruffy and you may need to offset the asking price against possible refurbishment and servicing costs.
Buy a used car from an independent car dealer
Specialists in a marque or type of car can be particularly good. Usually they specialise in older vehicles out of manufacturer warranty. They will of course offer a warranty, but check what it actually covers. Their stock will be cleaned, serviced and MOT’d before sale and they will part exchange your old car.
Buy a used car online
The joy of going online is that the whole wide world of used car classified ads and auction opportunities in front of you on a screen. Just because the car is online there is no reason why the normal rules of buying a used car should be ignored. You really do need to travel to see it. Do a lot of research about the seller, check feedback and like a real live auction, set a bidding limit and stick to it.
For the risk averse the dealers offer the safest way to buy a used car with plenty of reassurance that they will deal with any problems. Car supermarkets are a sort of halfway house with fixed pricing but lots of choice. Anyone after a deal will go down the privately advertised route and also online. There is a lot of room for negotiation and possibly getting a bargain. The downside is the lack of the protection, but for those savvy enough to take a chance they could get lucky.