Guys, I have few questions.. I would really appreciate if you guys can give me a clear explanation.

My car is 2003 Nissan 350z with BOSE system.
I am planning to buy Clarion NX509 or JVC KW-NX7000
http://www.sonicelectronix.com/item_...+-NX-509-.html

http://www.sonicelectronix.com/item_...KW-NX7000.html

1. Should I purchase PAC ROEM-NIS2 or just go with Metra wiring harness?

http://www.sonicelectronix.com/item_...ROEM-NIS2.html

I don't know anything about audio system but I've heard people saying with bose system, I need to use PAC ROEM_NIS2 to keep my factory amp and sub. Other people say with PAC ROEM, I might hear some noises, so just go with Metra. Insatalling with Metra harness wouldn't cause any problems keeping facotry amp and sub. I am really confused!! even the above website shows PAC Roem is for 1995-2002 nissan vehicles with Bose Audio Systems. My car is 2003 so I really don't know what to do. Can anyonen please tell me in detail???

2. If I only change head unit and keep factory speakers, amp and sub, am I going to hear some noises from speakers? that's what I heard from others.

3. I hear I am not able to use video system while driving.. If I simply don't connect green line that connects parking brake. Can I use it even my car is in motion? If not, is there any way to use it?

4. I can't find lots of information for Clarion navigation system. I personally liked Clarion sounds 5 years ago but I have no idea now. Which one has better navigation system? JVC or Clarion? I am currently in Canada so it should work well in Canada. Can anyone suggest me between two of them?

 

I have a Kenwood DNX8120 that has RCA outputs. I used the Metra 70-7551 harness. There is some hum if my iPod is in between songs or paused, but it goes away as soon as the music plays or I put the unit in standby.

I can't speak with much knowledge, but I think the PAC ROEM-NIS2 is better because you can "tune" the signal between the HU and the factory amp. I'm purely going by the little info that I have, but I know a lot of people on here recommend the PAC ROEM-NIS2.

I'm personally happy with the Metra unit, but it kind of depends on your taste I guess.

I know on my Kenwood, I just grounded the Parking Brake wire and I can play video while the car is moving. I think that's kind of a stupid feature anyway. What if you have a kid sitting in the passenger seat that wants to watch something?