I know that you're excited to join GTPlanet, and wish to learn all that you can about the Gran Turismo world, but please, please refrain from making so many new threads about topics that have already been covered in great detail. See that "Search" link under t fading car pictures? With that, you can dig up a heapful of information.
For example, a simple search of "glitch OR glitches" turns out the following: