Oilfield Trucking: Tank Gauging/Spill Prevention

I am with a company that makes a rugged electronic gauge and overfill prevention system for crude tankers in Canada and the USA. Drivers love it because it helps them load without spilling (display shows them the volume they are loading, alarms will sound or shut down the pump if they are getting too full), keeps them off the top of the tank, displays the loaded volume for their haul ticket, and they can trust it to work.

My questions:

- do oilfield tanker trailers in Mexico use a system like this already?
- are there spill/overfill concerns when loading?

Thanks,
Greg