We have a rather complicated situation to sort out, and I'm not sure where to get up-to-date information. Please help us figure out where to get reliable answers.

Our question can be summed up as, Can a US citizen drive a car owned by a Mexican citizen across the border into Mexico and leave the car there? What would be necessary to make that transaction happen, as far as ownership of the vehicle, taxes/fees, declarations, presence of the car's owner at the border, etc.?

Thank you for any and all leads.