I too have had problems with the exhaust system. I keep taking it back on one of those Lifetime Replacement guarantees - they hate me.
Recently I had to replace the pump on the windshield washer. It is pretty easy once you figure it is inside the fender behind the headlight on the bottom of the washer tank.
I had problems with a front brake overheating sporadically. Never would do it when I took it in, but it got hot enough to slow the car down - and too hot to touch.
Finally just had to replace the full rotor and brake assembly for about $200.
This was my daughters car and she left it here when she moved to Philly. I have so much fun driving it I can't sell it.
Is 40 mile per gallon the average?
40 mpg, hmm.. Is that just in the city, or highway or both? For a 96 OBD2 Metro it's not too bad. The Metro got a fair bit heavier in 96, so that little 3 cylinder engine has to work harder to move that weight around. Make sure you have the engine properly tuned, and check the O2 sensors (I believe OBD2 cars have more than one). Also, be sure to check www.teamswift.net and create yourself an account there and post on the message board.