I have written the same answer to your question in your thread regarding the sensors but I'll post it here aswell.
First of all congratulations and welcome to Pakwheels and the Belta owners and fan club, post some pictures of your new purchase so that everyone here can have a look see.
My Belta also has the same sensors on it's windshield. The sensors on the windshield are sensors for the toll tags in Japan, your car might have a ETC card reader aswell. The sensors at the toll tags recieve certain signals from the sensors on your cars windshield to see if has the data/amount to pass the toll tag. They're really interesting sensors, too bad they become useless when the car reaches Pakistan.
Your Belta has a Tv/Navigation system but not a Tv/Navigation/DVD system & player. What you can do in order to get the DVD's playing onto the Tv/Navigation screen is to get a 6-12 disc DVD changer, which would go underneath the driver or passenger side seat and a remote sensor which would be attached to your center console corner in order to make the remote work properly. OEM Tv/Navigation systems have certain sockets which make DVD/CD changers compatible. It'll cost you anywhere from PKR: 8,000-15,000 with installation (including the remote aswell).
P.S: Did you get the OEM Toyota Belta owners manual which is in Japanese? If you did get you'll be able to find out what I am talking about.