We have Sirius Satellite Radio, which we very much like. It's nice to be able to take long-distance trips and not have to switch radio stations all the time. The setups in one of our cars looks like this:
There are two ways for the Sirius radio get a signal the car's sound system. One is if there's a direct "auxiliary" input on the front, then you just plug it directly into the radio; that's most likely to be an option if you have a really nice radio (we don't have one). The other way is that the Sirius radio has an FM transmitter to connect to the car's FM radio. That can work by just putting the Sirius radio near the radio in the car. That doesn't work so well with ours. It was very easy for a terrestrial radio station to overpower the Sirius transmitter. I came up with taping the Sirius FM transmitting antenna to the car's radio antenna:
which works passably well. But driving cross-country, you still have to re-tune the radio for at least once every metropolitan area you go through.
Sirius does make a way to get around this. They makes a "Direct FM Adapter" that goes between the car's antenna and the radio that interrupts the outside radio signal. That eliminates interference from outside. However, to insert that, you need to get to the back of the radio. I tried to get to the antenna connection from underneath the dash, but I couldn't seem to get to it.
This morning I did a google search and found this web site about car stereos, which shows the tools to remove the radios in that car.
So today, I went out and picked up a set:
For size comparison:
Here are the holes in the radio where the removal tools go:
So I'll try this out.