I've recently discovered that someone in my neighborhood is using one of those in-car transmitters to put some external source on the radio. The problem is, it's left running all the time. I'm guessing that whoever it is doesn't realize that wherever it's plugged into is powered up even when the ignition is off. This is a Bad Thing. Those suckers tend to use a lot of power and this would be a really good way to end up with a dead battery. So, as a public service I'm reminding you to check and see whether your transmitter stays on the air 24/7 and to do something about it if it does. I wouldn't want you to be the one who ends up stuck with a dead battery.