In case you hadn't noticed, Chinese devices are frequently banned in Canada, especially for government use.
Chinese gear in telecom networks is either not allowed or being phased out. Chinese cellphones are not allowed for government use. Chinese apps are not allowed on government machines.
I do believe cars are a meaningful attack vector, with enough market penetration the ability to just "turn them off" could cripple the country, and there's not much point in letting them in if we limit the percentage down to something that would lessen the impact.