For only a few more dollars you can get a direct hardwired connection from your iPod to the factory NSX stereo that will sound as good as the CD player.
Here's a link to the photo tutorial that I put together:
http://www.legendtuner.com/LEGENDtuner/upgrades/iPodNSX.html
The USA*Spec adapter can be found at Circuit City for under $60. The installation is a piece of cake and the best part of using the USA*Spec is that you will be able to connect an additional audio source alongside the iPod.
Dont waste your money on FM transmitters or cassette tape adapters. Especially dont spend the extra $$ on "Made for iPod" versions of these things since the manufacturers are just profiting on the "iPod" hype.