I hit the 50K mark since I bought this car in January; we are now September as you can see I drive this little thing... A lot, what has gone wrong with it nothing, except the original muffler rusted out, literally just the muffler, the rest of the exhaust system is fine. Replaced the muffler myself for a grand total of 60$
The only downside of this car is the front seats are not very comfortable on long rides. Which is a small sacrifice, when I look at my insurance, and gas bills.
Add some Cushions & or some cushioning to your seats.
Watch out for the exhaust valve in the engine they are bad about burning out and causing the engine to only run on two cylinders.
I have 120K miles on my 1994 Geo Metro. I have only replaced the alternator and the muffler. Although it only has 3 cylinders, the car scoots like a champ because it is so light. I have learned to accept the slight crampness and tire noise. I had done extensive research (in terms of price, reliability, gas mileage), which led me to purchase the Geo. It is the best car I ever bought, including my VW Beetle and my Nissan, which were very good too. But the Geo is best.