eBay.com
seriously, i assume you're talking about this?
http://www.gforcechips.com/nissan370z.aspx
...you do realize you just bought a random IC chip (a resistor???) that'll do nothing, right? MSRP for 399.99...
btw you should've been tipped off already when it's trying to 'program through the IAT sensor'. riiiight.