Just because a brand isn't Canadian doesn't mean it's not part of Canada's GDP. Its the world economy now. If it's made in Canada, by Canadian employees, it count as Canada's GDP.
I'm arguing against you that Canadian manufacturing sector isn't negligible. It's certainly not as influential as energy sector, but certainly plays a significant role in the economy, involving thousands and thousands of family.
Honda has an assembly plant near Aurora, Toyota in Woodstock and Cambridge, GM in Ingersoll. Bombardier has tens of thousands of employees just in Canada. And obviously I haven't mentioned hundreds and thousands of individual manufacturers of all kind throughout Canada. (injection molding, metal fabrication, steel making, agriculture, you name it.)