maybe you should ask this board if they could recommend a decent shop, if you tell where you live.
Also, from my experience (as a customer and also as a former employee of an autoparts store), many " mechanics" have very gross idea about Volvo cars since Volvos are not as common as Ford, Toyota, etc.
For example, when my '95 850 developed noise my mech said: "make radio louder". After driving another 6-8 months noise got a lot worse -first he replaced PS pump -noise improved, but there still was "wining" sound on acceleration -next he replaced tensioner, again slightly better but still noisy and I remainded to him that he never listened to idler pulley -replaced it -no noise. 3 trips where should be one or two max.
Tell us where you are, and maybe someone here will help you to find decent+good mechanic.

PS

I used to work as a driver delivering parts to mechanics -about 30% needed my help to determine if aftermarket part was right or not. Out of 50 shops I delivered parts, I would take my own car to maybe 5-6...