What can one bring by car into Sonora, Mexico and what cannot be brought in?

Answer 1

This site that I looked at before going to Puerto Penasco a couple months ago shows what is considered "contraband" and tells you what to expect when you cross, which is helpful if you've never been there before.

Answer 2

Here's a site that has a link to the list of permitted and prohibited items:
http://www.sancarlosmexico.com/faq.html