My existing multi display is without navigation. I wish to change to with GPS.

What is your question?

The multi display with navigation is require more plugs than the one without navigation. Kindly advice how to modify to provide the require plugs. How to modify wiring?

What makes this problem better or worse?

Existing multi display needs ONE plug.

How long has your 2008 Lexus RX400h had this problem?

Multi display with navigation needs several plugs.