The guy that really made Grubbs outstanding, went back to school. Grubbs led the way in making the parts available, when every one else were scratching body parts trying to figure out what was being asked.
Today, you can get it numerous places. Look in the sat thread in the audio section and you'll find part numbers for what you want.
There are two different harnesses but they both work. You can buy them from dealers but most have no clue, so you have to ask them to get the part number. The best thing to do is a search on the web to see who's selling what.
Nissan has been playing a game with harness availability. If you can' t find one for the Murano, look for one for the G35. If they all dry up, look for a harness for the USA-SPEC CD Changer for Nissans. It works and was the first harness to show Sat worked in a 2003 Murano. You won't find it this cheap, ever, but I paid $9 for it in the spring of 2003, which was obviously the audio dealer cost. Makes you gag when you look at Nissan dealers charging $80-90 for the OEM one.
It's really quite nice having it integrated, if you want that clean look to the interior with nothing stuck on anywhere. However, the non-OEM with a Pac can work out slightly cheaper and on XM will give you more display detail, with the right solution. I don't look at the display much except when something's on and I want to know who or what, so the display works fine for that. Most of the time I listen.
It's great to have the presets work for your favourite channels as well as you can just flip through them on the steering wheel.
The OEM system costs more, and Nissan makes a ton of cash on it, but it's worth it for the integration.
You should also look at my web site below, for more detail on how it goes in.