Alan Stoker Automotives in Malaga is supposed to be pretty good, not sure how he goes with newer Volvos but I know he is quite knowledgeable with older ones.
Volvo in Osborne Park aren't supposed to be too bad but probably not as cheap as some of the other smaller shops that are around.
Have heard mixed reviews about Eurotech Autohaus in Bayswater, my manager had his BMW door locks replaced there and it was fine and some Volvo people swear by them, but other Volvo people have had some issues - botched clutch replacement, damaged interior when doing another job.
Andy (Polestar Technic) was pretty good but I think he has returned to working FIFO rather than continuing that business.
Hope that helps 🙂