For interior rattles, I used the headphones and directional Microphone stalk. For example, I thought my rattle on rough roads came from the centre console. But the microphone didn't pick up anything around there. It picked up a noise from the far left passenger footwell.
I removed the glove box and the noise was louder, so I knew I was getting close. I cable tied everything I could see that was loose, but it made no difference. The noise was loudest when I put the microphone right against the outer panel where the wheel arch is.
Pulling the wheel arch trim back only took a minute, and there was a 2cm rock in the front of the side skirt. It's amazing how much that sound could be heard inside the cabin. I also cable tied the Windshield washer hoses that were loose there, and could flap against the inner fender. There's no way I would've found that without this kit.
Noise is now gone, Success!
The kit also has 6 Clamps that go into a Switch Box. It lets you switch between different inputs, to see if the noise is louder at one spot or another. That's more for mechanical noises I think. I saw a YouTube video of a mechanic using it to see if a wheel bearing noise was coming from the L or R side. He switched between the 2 inputs, and it was totally clear which side the noise was coming from (one side made no noise, the other was grinding).