These are the least blingy thing you can do for your GTR. If you are looking for more noise, flash, HP or whatever - look elsewhere. All you get is a very nondescript switch and a little LED.
On the other hand - if you want your GTR to handle like its on rails - buy one of these. Very noticable improvement on the track and I did DECA last weekend with one in. OMG - they should ban the damm thing on a skid pad it is so good (very slick pad so I ran it at 7).