Buy one with a 5-speed manual transmission. I've had mine for nearly 5 years and 96,000 miles with virtually no maintenance other than routine oil changes, brakes (once) and tires (once). Everyone I've met who said that their Fiesta was a bad car had one with the poorly designed "automatic", i.e. dry clutch assisted manual, transmission that tended to leak oil onto the clutches and shift poorly. My 5-speed stick-shift has had no powertrain issues at all. I'm still getting 36 MPG driving a 60/40 highway/city commute. Even the original clutch is still smooth. The only parts of the car that are showing their age are the driver's seat and the floor mats. The driver's seat back is caving in a bit so it's lacking a little in the lumbar area now, but, hey, the car was under $20k out the door when new even with nearly all of the available options. All-in-all it's holding up very well for an econo-box commuter car. Just don't try to use the back seat for anyone over 4 feet tall.
I bought this used 2012 Fiesta about 4 months ago and have had way too many mechanical and electrical problems with a car barely 4 years old. Car needed new wheel bearings, then the check engine light came on the catalytic converter had failed, then the audio went out (thought a fuse blew. the problem is intermittent now),
I bought my 2012 Fiesta new, to date it has less than 40k on it, I do not drive a lot. However, there have been 4 recalls on it and it is currently in the shop for the second time in three months! First, they had to replace the clutch because of shuddering and jerking. Yesterday I had to have it towed to the shop for transmission issues. I am very disappointed in Ford and even though I have been a loyal Ford customer, this pretty much changes my mind. There is obvisouly as issue with the transmission, yet Ford doesn't want to spend the $$ to make a quality car.
When I first test drove this car I fell in love, but about a month later I sincerely regretted buying this car. The first problem I had was the catalytic converter end out at around 40,000 miles. Then it started shifting really weird when accelerating from a stop, it would stutter and shudder as if driving a manual and bogging down very badly. So I brought it to Ford and they said it was to be expected and they didn't know why it does that but it is normal, but they decided to try and recalibrate the transmission. The recalibration worked for a little while. Then the stuttering came back again so I brought it back into Ford and they put new transmission seals in claiming it might help, and again it stopped for a little while. But of course it came back and then they tried putting a new clutch in, which also helped for a while. So I finally got fed up with my fiesta and decided to trade it in for a new car, the salesman took it for a spin and was VERY concerned but they also didn't know what was going on and were only willing to give me $3,000 for my car when it booked at $7,000. So again I brought it to the Ford dealership and told them I was concerned about my transmission and the service guy was VERY rude he simply shut down my concern and told me I may need a new clutch, and then I told him that within the last year had already replaced that, then he went on saying that it is to be expected for the car to stutter and make noise while shifting. So DO NOT buy this car unless you are willing to put up with poor service and stuttering!!!