I Have 2 Head Units And I Want The Lockpick 3 Too

As mentioned in the title I have two head units the original one and the a eclipse cd3200 which is installer in the compartment below the original radio. Currently when I select audio button, it says audio off. obviously because the power is connected to the aftermarket radio and not to the original radio.

I want to install the LOCK PICK 3, would all I have to do is jump the contant, and accesory wire to the back of the original radio? and then hook up the LOCKPICK 3 (or any other video interface/connector)into the back original radio?

other questions:

Does the lockpick 3 allow you in anyway to install a navigation system program? or is just gives you and auxilary in so it can be hooked up to an external one?

What other options are there besides the LOCKPICK 3. I think they overcharged. Does the lockpick 3 involved some kind of microcontroller bridging or is it just a plug?

I own a basic 2007 prius

sorry for my noobie language