As you all know, I recently puchased my G35 and it only came with one key - the original Infiniti key. After inquiring with my local Infiniti dealership, they informed me they would only program an Infiniti key which they would sell to me for $125 and then program it for $45. I asked if they would program an aftermarket key, namely an Ilco key and they declined, stating they will only touch it if it has the Infiniti logo. This inspired me to figure out a way around the attempted monopoly.
I found an Ilco (iLco) key on ebay for $20.00 including shipping. I have been informed that iLco actually sells Infiniti the key they use. The model number for our G35 key from them is NI04T. Next, I researched the ilco website for the process to program the key and learned that it requires an SDD programming tool. [FN1] [FN2] [FN3] Next, I interviewed local locksmiths and found one with the SDD Programming tool and experience with Infiniti transponders. I made an appointment with him and he cut my iLco key, hooked the SDD programming tool to my car, acquired the four digit pin number, and re-programmed both of my keys. (it is necessary to have all keys when programming a new one). He charged me $65 to cut my iLco key and program it. It works perfectly, as does my original.
The bottom line is that you can avoid the costly dealerhip charges for the creation of an ignition key. This applies to all 2003 - 2005 G35's and am unsure what it takes for the 2006 key or if it is different. I was able to save over $85 and now have a functional key I can use as a backup or main key.
As for the remote control keyless entry FOB, I acquired one of these from ebay for $24 including shipping and programmed it myself, which was very easy. [FN4]
FN3: Also can be programmed by dealership using Original Diagnostic Equipment