What other non-car tests do you do on your songs, if any?
a typical type of test to do is just make sure you are walking around the room while listening to it, on speakers. i find this to be good practice. a lot of people sit squarely at the desk, facing the speakers the entire time, and i just think you are missing out on how the song is really going to affect someone living in the real world. so it is good to hear it while walking around, in a wide range of locations throughout the room, not just 'ground zero.'