Drugs.
Nothing was in there from the factory!
and chopped up hookers
...IN THE US!. In Brazil, my '97 Hilux SW4 has the exact same compartment and came with a warning triangle and a first aid kit. Both are required equipment in Brazil and several European countries. The triangle is secured by the rack and straps in there on both cars, but left empty in the US. I added one to my US 4Runner.
Cool, I always knew there was some use for those straps in there