The main pros -
* You won't pay new car sticker price; someone else will do that for you. The savings here can be enormous, even on a slightly-used (2-3 year old car), typically 20-30 percent or more.
* Because today's new cars are more reliable than the new cars of 10 or 20 years ago, today's used cars are more reliable, too. That means buying used is less risky than it ever has been.
* Because modern new car warranties are so good - in some cases, as long as 10 years/100,000 miles on major components such as the engine and transmission - the odds are good you'll be able to find a late-model used car that still has at least a portion of its original factory warranty (which is almost always fully transferrable to you) intact.
The main cons -
* Used car prices right now are actually upticking; in part because last year's "cash for clunkers" program reduced the inventory of used cars, in part because more buyers these days are shopping used rather than new as they try to cut back on expenses.
* If you plan to finance, expect to pay more for interest. And: Stay away from dealers that advertise "Buy here, pay here." These places are shark pools - and you are the chum. Shop your financing from a credit union or reputable bank - and get it all lined up before you start shopping for the vehicle.
* It's not new, so it may need maintenance/repair work - which could throw costs into the mix you didn't budget for.
Things to keep in mind -
* Try to shop when you don't have to. A mistake many people make is "emergency shopping" - they find themselves in sudden need of wheels - any wheels - and feel pressured to buy something - anything - ASAP. This is a great way to end up with the short end of the stick. Try to anticipate the need for a vehicle and shop for it at your leisure, on your own schedule. That will take the pressure off and help you make the right decision.
* Each used car is an individual. All new cars are pretty much the same. One dealer's brand-new F-150 is going to be the same as the dealer across town's brand-new F-150, so you don't have to worry about condition or how it was maintained. You can focus on price and other things. With a used car, condition is at least as important as price - arguably even more so. A good deal on a crappy car is not going to make you happy.
It's always a bit of a gamble when you buy a used vehicle, which is why it's smart to have any used car you're seriously thinking about buying inspected by a mechanic or shop you trust before you commit to buying.
* Research the rep. While relatively few late model cars (those built during the past 8-10 years or so) are out-and-out lemons or have major problems, some are - and more important (because the odds of it affecting you are higher) some makes/models can cost more to maintain, or need maintenance more often, than other cars in their class/segment.
For example, certain vehicles are known to be harder on tires than others, or seem to need brake work more often - or have a history of early transmission failures. Etc. These are things you want to know about before you buy.
You can get information about prior recalls and major known defects from the National Highway Traffic Safety Administration's searchable database at http://www.recalls.gov/nhtsa.html. Consumer Reports is a great resource for detailed information about any given vehicle's general record for upkeep costs and problems reported by owners. See http://www.consumerreports.org/cro/cars/index.htm.
Red Flags -
* Unusually low (or high) miles - Most of us consider low mileage to be a good thing - and most of the time, it is. Lower mileage usually means the car has more life left in it - and that you'll spend less on maintenance/repairs. Still, be wary of any vehicle with advertised mileage that's abnormally low for its age. It could be odometer fraud. Or (just as bad) it could be a mess from years of just "sitting there" - which can be as hard on a car as going to the dragstrip every weekend.
On the other end of the scale, cars with very high miles may be ex-rental or "fleet" cars - not necessarily a bad thing, but the bottom line is that miles on the clock equals wear and tear - and the more miles/wear-and-tear on a vehicle, the more likely it is you'll be spending money on repairs and maintenance.
Generally speaking, it's normal for a car to rack up about 10,000-12,000 miles per year for every year it's been in service. So, for example a 2007 model year vehicle would typically have about 30,000 miles or so on it. If it has significantly more (or less) miles on it than it ought to for the year, ask why - and be sure to get an answer that makes sense.
* Will it pass emissions? In areas where a successful "smog check" is necessary in order to register and gets plates for a car, be sure the vehicle will pass emissions before you buy it. You can use this as a haggling point, and if the seller's willing to knock the price down to allow for what it's going to cost you to get the car through smog, you'll be much happier with the deal.
* The "As Is" disclaimer - It should read "Whatever goes wrong is now your problem" - which would be more honest. When you see "As Is" on a bill of sale, be aware that most any problem that crops up after you take possession is going to be your problem. Caveat emptor.
Exceptions do exist for misrepresentation, which can involve fraud. But be aware that even if you're in the right, legally speaking, it can still be a huge hassle (and expense) to get your money back.
* "I'm selling it for a friend". . . This red flag should be as hard to miss as Michael Jackson asking if it's ok for your eight-year-old son to sleep over at his place. What you're probably dealing with here is a "curbstoner" - a person who buys and sell cars (usually, crappy ones) after a quick detailing and (sometimes) lots of Bondo and Motor Honey thrown in to mask a rotting shell and tired engine.
Curbstoners typically acquire the cars they sell on the cheap at wholesale auctions, or by purchasing them from others. They then clean them up a little - and sometimes fix obvious problems and place an ad in the classifieds or on Ebay representing the car as their own ... until you notice the name on the title and paperwork is different. Then they explain it's "a friend's car" - or maybe "Uncle Bob's." Walk away. Rapidly.
* It's already "warmed up" for your test drive. Never buy a used car you haven't had a chance to try starting up after it's been sitting overnight. If you don't you could be in for an unpleasant - and potentially expensive - suprise the morning after you've bought it.
Many mechanical/maintenance-related problems either show up or are much worse at cold start. For example, a worn-out engine will tend to clatter (valve/lifter problems), make tell-tale noises (rod knock/worn bearings), or smoke excessively when it's first started up in the morning. These are possible signs of major underlying problems which are sometimes masked or muted once the engine warms up. A problem with hard starting or erratic engine pefomance could also be hidden from you by a seller who has let the car "get ready" for half an hour before you arrive.
The Test Drive -
* If possible, test drive several of the same make/model vehicle before you commit to one; this will give you a better feel for what "normal" ought to be for that specific make/model of car or truck - which in turn may help you avoid buying the one that has a problem.
* Pay special attention to the oil pressure, temperature and Volt gauges (if equipped). A high or low reading (or vibrating needle/fluctuation) could hint at big problems you don't want to inherit.
* Make sure the "check engine" light comes on at initial start-up and then quickly goes out. If it doesn't come on at all - or stays on - there could be expensive issues with the emissions controls you don't want to deal with. Keep on shopping.
* Do an up-close physical inspection of the entire exterior; in particular, look for body panels that don't seem to align right as well as evidence of paint overspray on rubber trim around windows and doors, emblems and so on. Body panel alignment (including gaps between panels) on modern cars is extremely close-tolerance; if it's not, be suspicious the car was possibly in an accident. If you find any overspray, you'll know it was in an accident.
* Pop the trunk and smell the carpet (do this inside the cabin as well). If you smell a moldy smell, the car leaks at minimum and may have been flood damaged. Water damage is not worth messing with. Pass on this car.
* On a straight section of road, briefly relax your grip on the steering wheel to see whether the car tracks straight. If it doesn't, at minimum it needs an alignment but it could have more expensive suspension issues.
* Get up to about 45 mph on a straight section of road and apply the brakes firmly. The vehicle should stop straight and remain in control. If you feel a mushy pedal, vibration or the vehicle seems to take overly long to stop, it likely needs brake work. Maybe, more.
* The engine/transmission should not make any weird or excessively loud noises (again, if you took the time to test drive several of the make/model vehicle you're considering, something that's "not right" will be obvious). Be sure to operate all accessories, such as power windows, locks, cruise control, the stereo, AC system, etc.
The bottom line is, everything ought to work properly. And: listen to your Spider Sense. If something doesn't feel right or sound it probably isn't right. Move on to the next candidate.
