Has anyone ever used a product like this JS Audio CleanSweep "Audio Signal Summing Interface" to allow WX/ham radio audio to override whatever else you might be listening to through the AUX port in a car? The way I read the manual, I could hook up a weather radio to Input A, my 2M radio's speaker output to Input B, and my iPhone audio to Input C. This would prioritize the signal such that the WX radio's alert would override everything, the 2M radio next, and then my iPhone music if nothing else is going on.
Is there a some other approach to getting 2-way radio output to car speakers while maintaining the ability to jack in music or podcasts? Is there some option for a splitter box like this that does not cost $140?
Here's the product: http://www.amazon.com/JL-Audio-CleanSweep-Summing-Interface/dp/B000TD6SR2/