I have been pricing the installation of satellite radio into my 2007 IS250. Since it already has the NAV button and a sharksfin antenna, I thought any equipment needed to get it working would be minimal. Boy, was I wrong! The dealers in Phoenix want almost $800 for XM! Well, thats out. I simply don't want satellite radio THAT bad. But I might be willing to spend $300 and do it myself if its not that difficult. Apparently you need two units: the tuner (Sirius or XM) and an interface that allows you to use all the dash and steering wheel controls. I am researching now, will report what I find out. In the meantime, has anyone already done this? I am particularly interested in using the existing sharksfin antenna.