Some people insist on servicing their own cars. Not me. I rather have the experts do it, even if it costs more.
I've used Toyota City Service in Mapunapuna for several years. Service is available Monday through Saturday, though Saturday is only a half day for them. I usually drop my car off during the work week and take advantage of their round-trip shuttle service.
Loaner cars are available for longer-term repairs. The Toyota Echos will make you appreciate your own vehicle even more (unless, of course, you actually drive an Echo).
One issue I've encountered lately is that they seem to be understaffed, overworked, or both. Even simple oil-change appointments have to be schedule a month in advance. The quality of the service work seems to have slipped a notch as well, almost as if they are rushing to complete each job. I had to bring my car back twice due to sloppy reassembling of the area that they "fixed."