Maybe Toyota and dealers in Ontario are not interested in repeat business, but we haven't used dealers for servicing for a long time, and as I said, never had any issues regarding warranty work. Now, I do use OE filters and parts and keep receipts and carefully document the services, just in case. OE filters are one area where the OE part is generally of much better quality anyway.
The Mercedes dealer did note once that my slightly oversized non-OE alloy wheels might cause me problems if steering or suspension parts failed, but otherwise, not being dealer serviced has never been an issue.
I'd be interested to know what warranty costs are for different manufacturers. Mercedes spent over $10K on warranty repairs on our C230, and probably close to $10K on our E300. The Forester had one front O2 sensor replaced, for a total of ~$500. The Corolla had an issue with a variable timing gear oil supply that caused a lot of racket at start up, and that's been it. Of course, we should have been denied that coverage, not having using Toyota oil (Amsoil, OMG) and not have used a Toyota dealer for oil changes. Interesting that we weren't even asked about oil change history...