If you are asking if you can add navi to your integrated radio/display the answer is no. Components to enable navigation are missing throughout the infrastructure of the vehicle. Purchase a Garmin!
If I understand, the factory JBL radio is not working and you want to replace it? To maintain steering wheel functionality and integration with the display screen, you can replace it with a used one from a junkyard or online. Plenty should be available for the GenII... If you want to upgrade to the six disc Premium JBL, I would think it would be possible, but you may have to play with the wiring harness. For that, I digress to another user who has performed the upgrade.
And do you know online web or junkyard that sell cheap price and good condition .... and I can't find this one ??? Thanks
instead of trying to retrofit the jbl system, which isn't great, why not buy an aftermarket double din head unit which has everything you want, and then replace the junk factory speakers too. you'll have a way better system and it will cost less than taking the whole interior apart to rewire and trying to get all the other mediocre jbl parts.
any double din unit will fit. you need to figure out which one you want. you need to determine which features you need. i would buy from crutchfield.com
Like I said, I am not familiar with what wiring harness you would need. I would go with the above users suggestion. Good luck!