The headlights will work, but the bumpers are a little wider than the 03-05s.

 

I know this is an old post. but....

You can get the LED lights that come on the '06 for $398/pr. here:

http://www.courtesyparts.com/350z/exterior.html

 

My first question is why?? The money you will spend to "update" you Z could be spent to get a body kit. I have an '05 and I bought the full Greddy kit. It makes the car look like the hot chick next door!! Nice but nasty!! The kit cost $1K + paint & install $1500 ( had the battery & brake covers painted at the same time). You could also check out the Aerosync front bumper ( Z1Auto.com) for about $600...looks really nice and is made of the same material as the OEM bumper!! Just my 2c