-- Replaced intake manifold gasket (89k miles). This is a known problem with the original gaskets, dealer did it the day after I took the car, when I noticed the leak. Free.
-- Replaced crank position sensor (92k miles). Another known problem. Car was stalling occasionally on highway or under load. Problem solved. $150.
-- New alternator (94k). Original one gave up the ghost on a highway trip. Bought a new one and replaced it by hand in a parking lot with one wrench in about 20 minutes. $110.
-- New water pump and drive belt. (95k miles). The original pump was on the way out, and the wobble in its pulley ruined the drive belt too, which wouldn't have happened if I'd replaced it when it started squealing. $210.
Other existing problems: intermittent steering pull, probably a suspension bushing. Driver's side lock is frozen (electrics work fine). Intermittent rev problem only when engine gets very hot as in a traffic jam, 2 mechanics can't figure out what it is, though likely an electrical issue.
Other work done: new plugs and cables, new wipers, filters, oil. Recharged the dead A/C with a cheap kit, works fine now. Touched up the paint. Nothing special.
This was a low-mile one-owner car I bought at a used dealer, with a pristine interior, good body, and amazingly with every last electric feature in good working order. All the maintenance I've done or am likely to do in the next year is standard 80-100k mileage stuff. Nothing except the alternator has left me stranded so far, and I've been impressed at how well the car is put together, and even (gasp!) engineered. Also, note how cheap the repairs have been. Peanuts.
I've been getting around 17 mpg city, 26 highway, 27 if I keep the speed below 70. The car loves the highway, and is a far more comfortable a cruiser than anything else I've owned, and as much as any I've driven, including a Lexus ES300 and a Volvo V50. Part of this comfort is due to the huge and plush interior (front and rear), covered in the hides of a dozen velours. The back seat doesn't fold, but a seven foot long IKEA bed kit fit into the reclined passenger seat with room to spare.
I prefer this car to several old Volvos (240 wagons and a 164) and an Audi (5000 wagon) I've owned: it's more powerful and just feels more substantial both in construction and on the road. The Gran Touring suspension handles better than you'd expect from a Buick, though I've contemplated going for firmer shocks/struts to tighten it up. Power on the stock 3.8 is fine, not fast but has plenty of torque at low revs for ordinary driving. The transmission is excellent for an automatic. The stock front disc/rear drum brakes are a bit weak.
Now that I've got this car nearly sorted, I'm tempted to sink a little time and money in it: with stiffer suspension, better brakes and tires, and a few power tweaks (the usual 3800 supercharger and more open intake, if I get energetic), it would make a wonderful sleeper sport sedan: comfy, confident, and at lower total cost than a transmission rebuild on a late-model 3-series BMW. It's essentially what Olds did to the last-series LSS, which has the same bones as this car -- I just prefer the Buick styling and interior. Plus I already have a Buick.