For example let's say I have an automotive site and I have a 'Make' dropdown with "BMW, Chevy, Chrysler, Dodge, Ford, etc" and if select "Ford" I want another 'Model' dropdown to only display only Ford models like 'Focus, Mustang, F150, etc."
Is this a good use case for Query Args? I would appreciate a link or two on how to use Query Args too.
Yes, you can create a CPT make with some parent posts BMW, Chevy, Chrysler, Dodge, Ford and child posts. Then use the field post with the field type select_tree or checkbox_tree. Screenshot https://share.getcloudapp.com/rRuWLe2e