read this forum carefully.
Here is a quick rundown of problems the focus has:
Clunking/shuddering transmission (DCT)
Transmission seals failing which require clutch replacement (DCT)
DCT transmission overheating in traffic and requiring a rest period to cool down
Gas Mileage ranging from OVER the rated mpg, or gas mileage falling WELL BELOW (such as myself and dozens of other people here) the rated numbers
Those are the biggest problems.
If you are getting the manual, you can avoid most of these problems.
If you have any major issues, be prepared to be given the run around by ford service.
Mods: Drop in K&N filter, Steeda RSB, MS3 RMM, Remote start, Llumar tint, Ti engine cover, Husky floor mats, OEM splash guards