Unlocking Trunk Lid
WARNING: This page is about a different car, the 2003 Lexus IS 300 and 2002 Lexus IS 300. However, it is still accessible from the selected car via links, so may be relevant.
When you keep the button pushed for about 1 second, you can unlock the trunk lid (operation method can be changed). This function does not work when the key is in the ignition switch.