They ARE trying to stop people pulling local copies. Under the T&Cs you don't have the legal right to full time access to the information, only with a valid in-life subscription.
As a point of reference, and in no way suggesting Toyota's copyright should be broken using such methods, taking screenshots isn't the best way if the pages are long as you need to take multiple images, scrolling in-between, and the resulting images are large and not searchable.
Most browsers has a save-as feature but typically don't work very well. Safari seems the best here because the save-as creates a full archive of all the page components so it views perfectly again, but you need to be a Mac user.