I messed with the L/R delay a little more today and noticed that in my car, I need to move it in the opposite direction as I do when listening on headphones. And my car is not wired backwards (balance is still correct), it's just that my soundstage isn't particularly distinct in my setup (I only have door speakers) and the rear speakers are louder than they should be for proper soundstaging. It's all about reflections etc...