Thanks Rez for calling me out..
I have raced the 500 and 1000 but years ago. Not sure on the pricing, but you will need pit/chase support to do a race like this. You will also need to take time off to go down and pre-run your sections which is highly recommended. You will need a minimum of a week to do that. Taking your bike and enclosed over the boarder is no big deal.
I would stop just before going over the border and get mexico insurance on your car and trailer for piece of mind. Racing in mexico takes a lot of support and I would not just show up and race. Back when I did it, I was linked up with Team Green and they supplied my pit support/parts and my dad was my chase driver. He would be at the pits that I need to switch off the bike and get me to the next bike swap.
is another thing that you have to do, you cannot just throw your bike in the truck and head down there, you need to make a few safety additions (not sure what they are now) and make sure your bike is sound and going to make it. I would plan on bring a handful of filter changes and Filter Skins.