As with any turbocharged car, maintenance is extremely important. If the car has not had regular service, including oil changes, you could end up with a money pit.

A well maintained 740/940 turbo should have 250,000 miles in it before the engine needs attention. At that point, it will need a headgasket and you might as well refurbish the head at the same time. The bottom end should last "forever."

At some point, the turbo will need rebuilding due to worn seals and/or play in the bearings. This could happen anywhere between 150,000-200,000 miles. The car will start blowing blue smoke if the seals in the turbo are on their way out.

The rest of the car is pretty simple for a 1992 model, and therefore very reliable. These cars do tend to go through motor mounts and suspension bits more frequently than other cars. The exhaust is also a weak point. You'll end up replacing the exhaust every 3-5 years, perhaps more often if you live in the rust belt. However, this is not a particularly expensive repair. Maybe $500-$600 at a chain place that does exhausts.