If you lift the load bay carpet you'll find four plastic inserts protecting the rear cargo bay threaded tie down points. They are 5/8UNF thread I think.
These are what I've used for my rear storage system and you don't have to drop the tank or crawl underneah to use them.
I suggest you apply a generous ammount of copperslip or anti-seize compound to the bolts when you put them in.
S.

