The popular 3-button and 4-button keyless entry remote keyfobs with FCC IDs KBRASTU15, CWTWB1U415 and CWTWB1U733 are available on the Remotes Unlimited web site at a great price. The dealer list price on both of these parts is over $100 and this website is selling them for $69. Check it out.
These remotes were used on many Nissan and Infiniti vehicles from 2001 to the present.