You can normally find some pretty good deals at used car dealerships. However the hard part is knowing how good the deal is versus how bad. You never really know exactly when that car will breakdown just like you do not know when someone will die. However if you have cancer or your car has a transmission issues you can pretty much bet that time is coming close to a end.
With that you want to make sure the health is in top shape and you are taking your vitamins. Bringing your car to the mechanic garage for check ups every 3 months should be mandatory when you have a used car over 100 thousand miles. If not you are asking for it. Most older people go see their doctor more often because they know time is fragile.
You should think of you car in the same way and make sure you also add a insurance or warranty policy to protect against serious surgeries etc that you may be required to fix. Just ask your mechanic what he or she recommends and you should be fine. However like myself, like to have 2 doctors you may want to have 2 mechanics. Just saying, those costs are up to you of course see this website to find other car dealers.