It generally works as you would expect. Sometimes however, when I turn on the head-unit, the radio is completely silent, and sometimes it is not recognized at all, the standard tuner is the only option available on the head unit. To get it to work, I usually need to stop the car, and turn it off. That seems to reset everything. Just turning the radio itself off and turning it back on does not fix it. Only turning off the car entirely (and thus shutting off power to the unit). This somewhat of an annoyance, it usually works. Only 10 percent of the time do I have this problem, and restarting the car always fixes it. The most annoying thing is to discover it is not working when you are on the freeway, you are kind of stuck, unless you pull off the freeway so you can restart your car. Also the unit seems needlessly large, I don't know why these Alpine add-ons are always so large. It takes up half the space under my set. Low score on design. Sonic Electronix was very helpful in the placing of my order.