I am the original owner of a 2004 buick rainer. I have had some of the problems stated.
1. Panel cluster failure, which gm should be ashamed of with all the complaints.
2. 3 water pumps.
3. the vacum cleaner sound, which is a bad pump under the driver seat, if the pump has water in it ,its a valve that attaches to the engine.
4. the abs module which you have to have sent off and repaired
5. the sagging rear which I have yet to check out
6. vibration when idleing still trying to figure this one out, will replace fuel filter as some suggest.
7. oxygen sensor
8. oh and fuel injection cleaning for stalling, which did work.
I have over 220,000 miles on my girl and overall think it is a well made vehicle. My husband has a 2010 ford pickup that has been in the shop and has left him stranded, mine has never done that. when my gages went crazy I never ran out of gas because i filled up every few days, annoying yes.