I'm also in the GTA and generally tend to go with either:
http://www.tires23.com/index.html
or
http://www.kiplingtire.ca/about.html
I am in no way affiliated with either, but have received good service and prices from both. I would do business with them again.
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2019 Golf R 6MT - current daily...I need another coupe
2008 Civic Si - winter beater
2000 Silverstone M5 6MT - SOLD
2013 Ultramarine FR-S 6MT -
Car Journal - SOLD
2004 AlpineWhite M3 6MT - SOLD