Outside Online magazine/blog reminds us that, while you are prohibited by your rental agreement from driving a rented car or truck into Mexico, you can rent a motorcycle in San Diego and ride south.
https://www.outsideonline.com/2183431/how-visit-baja-motorcycle-no-motorcycle-required
The article also has several useful tips about riding in Baja.
https://www.outsideonline.com/2183431/how-visit-baja-motorcycle-no-motorcycle-required
The article also has several useful tips about riding in Baja.