Why were the gadgets in the Lamberghini in "The Spy Who Loved Me?" weren't revealed at the beginning?

We found out later the toys of that famous luxury car from the 1977 James Bond movie...a surface-to-air missile firing system, the ability for the car to swim underwater, torpedo missiles, a smoke screen, and what I call a "depth charge" bomb in a form a hockey puck...designed to explode underwater when the bomb hits the underwater surface. Looks like the screenwriter did a good job...he did not tell us what was in that car even when "Q" tried to mention the items to both James Bond and XXX Russian agent, Major Anna. All of that gadgetry stuff was revealed in that famous chase scenes ever that I loved in any Bond movie.