this may change my travel plans to Zihua next month

There is no problem with driving from the US into Mexico. Yes, I have verification of that several times over.

I have heard reliable reports of Canadians having their vehicle transported, via flatbed I believe, into the US, then flying to the US, meeting their vehicle then driving down.

I have at least one Canadian who is prepared to do that from Mexico to the US if necessary. The necessity of that has not been determined.

Come paddle, buy the house, stay.