The only difference between that and actual kickpanels is the disatnce from your ear to each speaker is increased with kickpanels, which is why they are seen in high end systems. The idea is to get the speakers as far away as possible so the sounds from each side reach your ears at the same time. Many HUs now offer adjustments to tailor the music to a certain seating position but generally this messes the sound up for the passenger (I know, it isn't his car, but half the fun in this is props for your hard work when you crank the volume).
