purebliss

I saw a pretty nice GS300 proably a 01 or 02. Not an 03 because it had the old size goodyear tires on it. As I always do with any gs I took a peek inside it. I saw the radio controls on the steerling wheel. At first I though maybe they were the lexus car phone controls but as I looked closer they were the same as the ones on my GS430. Now my friend bought my old GS300 and when I told him about this car he wanted to know how to do it. You guys every hear of doing this mod? I mean the car had the stock radio no ML. Any ideas out there on how to do it? Do you think there prewired? Any info would be great! Thanks