A few people who post on here need to be placed in a padded wall room, not just the floor. Anyway might try Home Depot, believe they have inter locking rubber floor mats. Mostly used for home/garage workshops. But should work for your gym.
Yeah, not too many go over the border any more. At lease around TJ, Tecate or Mexicali. Bad times. Only highschool kids on the weekends (stupid stuff really), lifters and tourist from back east.