If you're going to buy used, it's generally better to buy from a new car dealer rather than a used car lot. You may not get a warranty but at least they pay more attention to safety items like tires and brakes, and they're at least nominally interested in their reputation.
Then again, if you have only a few hundred to spend you're not likely to find anything at a dealership, whose bottom-of-the-barrel stuff usually starts around 2000, and in which case you're not going to get a reliable car anyway. Unless you can get Grandpa to sell you that old F-150 he only drove to church twice a week.
Yes, the DUmmy, one of The Smartest People On Earthâ„¢, is screwn. Taken by a used car saleman, just like Obama.
On the bright side, maybe Global Warming will defrost us and bring an early Spring so you can give that bicycle a workout.