(in response to the link you posted)to tune your sound to its best, get some bass test audio and tweak the gains until you get the clearest sound. bass will travel through your car but mids and tops just bounce of objects.
turn your stereo to a volume that you would most use and set the bass to such an extent that it isn't the most dominant sound coming from the speaker. because bass is omnidirectional, you don't need much of it to get the rich sounds you are looking for. you don't want to hear any vibrations from the car other than the bass. once you get vibrations from the car, your sound will be distorted and spending all that cash for better quality sound will be nothing but a waste.