My car has the infamous 3.8 litre engine. I like that it has relatively high low end torque, but I don't like the fact that this engine has head gasket troubles. So far, no problems (knock on wood).
Since the rebuild of the transmission, I have put over 6000 miles without any problems. I hope that this reliability trend remains in effect for as long as I own this car.
If you are wanting to get a Ford Taurus or a Mercury Sable, here are a few pointers.
Make sure the transmission updates are applied, which includes updated steel forward accumulator piston, enlarged lube bore hole, and updated lube tubes.
For added protection to the transmission, invest in an auxiliary transmission fluid cooler and have it installed. Believe me, the investment in this part is more than worth it for any car, but particularly for the Ford AX series transmissions as they run unusually hot in normal conditions! Remember, every 20*F decrease of the fluid temperature will almost double the life of your transmission.
Another idea is to have a transmission shop install a shift-kit to reduce wear on the clutches. The shifts will feel harder, but that's a good thing. This means that the clutches are not slipping as badly as they would before the shift kit application. Less slipping equals less wear. This means the transmission will last longer.
Transmission mechanics do make a killing on the AX transmissions. They are decent when their design problems are addressed, but it seems Ford was careless when they engineered them.
For the engine, get a Sable or Taurus with the 3.0. It doesn't have as much low end torque as the 3.8, but who cares about acceleration if the gasket decides to leak coolant in the oil? The 3.0, on the other hand, is a reliable workhorse. Besides, the AXOD-E, AX4N, and AX4S are not really able to deal with the additional torque from the 3.8.
If you want the 3.8, check the coolant and oil before buying the car. If the coolant level seems low, if the coolant has oil, and/or if the engine oil has the appearance of chocolate milk, DO NOT buy the car.
If you are still unsure, forget Ford. In fact, forget American cars in general. Regardless to what anyone may tell you, there is still a quality deficit between the American big three and the Japanese. Buy a Honda Accord or a Toyota Camry. In addition to being more reliable, they also have fantastic resale value. They are just a bit more expensive to buy, though.
Cautious discretion still applies if you are buying any used automobile since there are crooks out there who will try to sell you a bad car.
A car, regardless of who made it, is only as good as the person who originally owned it. Certain exceptions do apply, though. The original owner may not have been able to help the fact that the car he owned might have been a lemon.
Also, consider what may have happened to the car to allow its sale to the used car buyer. This reinforces the value of checking in on a potential car's title history with "CarFax" or another reputable reporting firm.
Hope this helps. - Reinhart.