For vehicle insurance we have always used (13 years)
Lewis and Lewis and can recommend them. we had a problem with a claim a year ago and Lewis and Lewis (Insurance Brokers) were very helpful in dealing with the adjuster.
I would also highly recommend
the Churchs' Baha book We are experienced Mexico RVers and wouldn't think of going down without their Mexico Camping book.
Take copies of your marriage certificate. In the case of emergency you must to be able to prove that each of you have the right to look after the other.
Note that should you go over to mainland Mexico you will need different insurance and vehicle import permits.
Have a great trip.