Couple of OZ surfers missing in Mexico

We do not do Facebook (privacy issues) so may have missed something. Was there something in the press that said there was no license plate? Are we sure they were driving at night or just assuming? What reason might the cartel have for doing something like this - doesn't seem like something they would do - why? Can we wait for the full police report? Or should each of us dream up our own story? Please post any news reports that present facts from the authorities.