No, you could belong to the CAW too. 
:
Magna supplies GM and they are notorious for not being unionized, (though that might be changing to a degree soon)
Do you mean does GM only take parts from unionized companies? (answer is no.)
Or are you asking, if you work for a unionized company in a job that would be part of the union do you HAVE to be a union member? (the technical answer is it depends on the place, but the general answer is yes, pretty much.)
:Magna supplies GM and they are notorious for not being unionized, (though that might be changing to a degree soon
)Do you mean does GM only take parts from unionized companies? (answer is no.)
Or are you asking, if you work for a unionized company in a job that would be part of the union do you HAVE to be a union member? (the technical answer is it depends on the place, but the general answer is yes, pretty much.)
