Why did GM cars stop using driving lights.

The law must of changed, and without the law they wouldn't spend more money than needed.

I have not heard that GM removed the headlights on all it's cars. Apparently you are the only one to notice. You should call the local news station and report this before someone gets killed.

For years, GM pushed for them to be made mandatory, supposedly because they would eventually make money selling replacement parts and conversion kits.  While they are mandatory in other nations, our Government resisted to do the same here, claiming our driving conditions are different.  GM finally gave up on the idea.