They turned up this weekend from
http://www.nengun.com/nismo/carbon-pill ... h-for-350z
as recommended by Gus and also the best price I've found.
Really pleased with them and can't fault nengum either
I think if the Head unit has been replaced you should ge at least 1 years guarantee with it. I know with Audi you got 2 years.
Maybe someone else can confirm