Tracking your driving habits is a privacy violation but not the biggest issue with Chinese cars. The Chinese government has unrestricted access to collected data AND they can compel manufactures to collect specific kinds of data. That turns Chinese cars into a fleet or war drivers.

With thousands of vehicles recording every WiFi point and bluetooth device that passes in range you can track other devices and other vehicles that are not of Chinese origin. For example, a politician or members of that politician's entourage could have their phone's wifi and bt mac identified at a public event by a Chinese agent. From that point on they can be tracked anytime they pass within a hundred meters of a Chinese car. Even if the VIP is practicing good opsec their entourage may have a personal device that is identifiable. This would let the Chinese government get a heads up on meetings with businesses or other heads of state about which they would not have otherwise known.

And this is the most trivial example, it would require so little data transmission from each car that it could be hidden in regular diagnostic and update communications.