Is there any difference btw 03 and 06 air box if they are please kindly tell me what it is and post some pic. Did search and everyone just said 06 air box is good but did not explain or post pic to say why and what is the difference btw 03 and 06 air box.

 

https://my350z.com/forum/showthread....hlight=v+stack

Read through here. Look at Wired24/7 post.

 

Here's some pics that show the difference.
https://my350z.com/forum/intake-exhaust/293716-pic-request-inside-2006-oem-airbox.html

 

where can i get the 06 air box? no one is selling, do you think i can get one of the velocity stack from ebay and put them in my 03 airbox?

 

Maybe you can go to the marketplace and start a "Want To Buy" thread for the 06 air box. Look in the personal classifieds as well.