I get more confused looks than mean ones, so I usually just shrug it off. Although a common retort is "That sounds more like CHINESE than JAPANESE, thank you!" (In regards to "zomg ching chang chung!")
But of course it's cool when my host sister listens to it!
Obviously it's okay for her to listen to it because she can understand it. *rolls eyes*
If somebody ever messed with the music I was listening to in my car, I'd probably tell them to get out! Sort of like smoking, ha ha.