I know this tread is old. I was looking to replace the "nagare" bulbs in my 13 GT. Sounds like not a lot of people have done it, but I found a thread on another forum.
It's super simple. Get some T10 wedge-style LEDs. I think these are the same as the license plate and glove-box bulbs. Slowly twist the stock bulb housings counter-clockwise from the back of the headlight housing. Slowly pull the old bulbs out. Insert the LED replacements in to the bulb holder. NOTE: Before you insert them back in the housing, check that they work because the polarity only works one way. If they don't work pull the bulb out and reinsert it the other way (clocked 180į). Insert the bulb assembly back into the headlight housing, slowly twist clockwise. SMILE.
LEDs match the stock HIDs soo much better. The next problem will be the foggers will look like total crap. I tried some cheap H11 replacements but they were too long and fit like crap. So I ordered the fog kit from corksport. Works awesome. All lights now at about 6000K!