There are lots of places to buy a used car; from private sellers to traders of different kinds - or if you're feeling adventurous (and probably not just a little bit reckless) you could even go to an auction.
As a rule of thumb, the more legwork you put in, the greater the savings. And another general rule says that the more money you pay, the greater your peace of mind. But that latter rule is far from universal, so don't assume that paying top dollar will guarantee trouble-free ownership...
As a rule of thumb, the more legwork you put in, the greater the savings
Buying privately: this route is generally the cheapest way of buying a used car, but beware of over-optimistic pricing and there’s no warranty. The key is to make thorough checks on any potential purchase and if the car will need any cash spending on it in the short term, haggle the cost of doing this work off the seller's asking price.
Franchised dealers: these usually have newer cars in stock, which will often be better cared for and have lower mileages. The downside is they also charge the most in general, and while they'll be your best mate up to the point of purchase, once they've got your cash there's no guarantee that you'll be quite so loved. However, the weight of consumer law is on your side if they sell you reall lemon then fail to do anything about it.
Independent dealers: these usually offer the same facilities as a franchised dealer, but the cars tend to be higher mileage. Again, you've got lots of consumer protection, but as with the franchised dealers there's no guarantee that you'll be looked after. For the optimum balance of value and peace of mind, the independent car trader tends to be the best best.
Car supermarkets: these offer low prices as they sell lots of cars and make a small profit on each. They tend to focus on mainstream cars only, but there’s usually plenty of choice. However, if problems crop up post-sale, you might struggle to get effective fixes quickly as supermarkets don't specialise, so they don't have the marque-specific expertise that a franchised dealer would have.
Auctions: the lowest prices are here, but it’s easy to buy a duffer if you’re not careful. Buy here with caution as there may be very little comeback in the event of problems.