I want to install the bt-45 infi, and hear its real simple and a good way to add bluetooth to the vehicle, my transmitter is really starting to annoy me and want to upgrade. I had heard that the only issue is that it constantly draws power and can drain the battery flat, Its my daily but I dont drive every day and the car sometimes sits for a 3-4 days, is there any way to stop the constant power draw?
thanks in advance!

USASPEC doesn't provide a pinout for their connectors that I can find, but the instructions say it uses the factory prewire connector. If it's using battery power at all, it has to be for purposes of being "instant on" with the ignition. So I'd presume you can modify their prewire interface to use Ignition or Battery Saver power instead of Batt+ if you're willing to accept a boot-up delay. The factory prewires have some differences across models but the Batt, Ignition, and ground pin positions are standard, and I believe the Batt Saver position on the connector will be standard as well. Here's the layout taken from a '17 Murano:

If you modify the BT-45's prewire connector so that whatever wire is going into pin 2 (Batt+) is cut and spliced to the wire on pin 1 (Ignition) or pin 5 (Batt Saver), the BT-45 should only get power when those pins are live and should be unable to suck down the battery. The prewire connector layout shown is for the Nissan pigtail which mates with the car, so ignore the wire colors. To orient the pin numbers, the diagram is shown looking at the pigtail from the wire side, so the view is essentially looking into the cavity of the prewire connector on the car. Just cut the wire on the BT-45 harness which mates with pin 2 and splice it to either 1 or 5.

Some stuff on M's is weird compared to other N/I products, so I'd definitely advise using a test lamp to confirm the power layout on the connector before cutting anything. The Batt+ pin will have constant power, the Ignition pin will cycle on and off with the key, and the Batt Saver will cycle on with the key but off 10~20 minutes after key-off.