Strange Rattle When Brakes Applied

Let me start off with some basic background information. The car is a 2009 3.0R. I got it new and it's about a year and 5 months old. There's about 30k KMs on the car, and mods so far are JDM Bilstein Spec B rev. C's with Tanabe NF210 springs and STi quad tip exhaust.

 

Now, onto the issue. Over the past little while, maybe a week or two, I've noticed this really strange rattling noise in the car. It seems as if the rattle is coming from the passenger side, and it may possibly be located in the engine bay. This rattle occurs when I'm braking, specifically when the car comes to near a full stop or is at a complete stop. As soon as I take my foot off the brake pedal, the rattle seems to quite down a bit. If I apply some throttle, the rattle seems to go away completely and not because it's being drowned out by the engine noise.

 

When my exams are finished I plan taking it into the dealer to get them to look at it. Unfortunately, I haven't had anyone in the car that would be able to check take a look in the engine bay to see if they can pinpoint this 'rattle' while I'm applying the brakes. It almost sounds like when you take a fan and sort of stick a pencil slightly in the path of the spinning blades.

 

I should mention that the overall performance of the car hasn't changed. I do not feel any brake hesitation, or any abnormal vibrations while using the car. It's just rather annoying when combined with all of the other squeaks and rattles that we've grown accustom to with the Legacy.

 

Does anyone have any idea what this could be?

bump for help?

torque converter, my noise raddle occured when i put into reverse, pushed the braek, not saying it is, just saying maybeee.