If you are driving I'd think it would be easier and faster to cross into Mexico from Texas and stick closer to the gulf coast, no?
What I'd really like to do is to find a dependable service that could store my car in Playa or Cancun then deliver to you at the airport. I'd think somebody mechanically minded with a chunk of land outside Cancun could make a good little business of this. It would easily be worth several hundred a year to me. Car rental is my single biggest expense when I visit the Yucatan