Grubbs Infinti very large dealer does a lot of retail all over:
http://www.grubbsinfiniti.com/en_US/
Pinnacle Infinti: Also dealer with very large inventory this is a link to their parts section but if you call this #, I am sure they will be happy to punch you thru to new car sales:
http://www.nissanparts.org/
Scottsdale Infiniti: Perhaps the higehst volume dealer of them all (except maybe Grubbs, I am unsure which is bigger, they both claim to be the biggest in USA or at least they used to), again this is their parts site but just ask for car sales.
http://www.infinitipartsusa.com/
Be sure to mention you are from NICO as this will likely get you a little extra personal attention and maybe even a discount.
Fred..