Stopping Cancellation in Ported Enclosure

The following article talks about cancellation in ported enclosures caused by the sound waves from the front and back side of the subwoofer cone being out of phase with each other at the point in which they come in contact.  I am trying to design a ported enclosure for a '97 4 door Civic.  The enclosure would hold 3 12's, and will be constructed from fiberglas and mdf.  The article basically says that to prevent cancellation the rear wave should travel 3 times the distance of the front wave before it hits your ear to become in phase.  I have several questions regarding this theory.  First of all is this always true.  I have read about front and rear wave cancellation but I have never before seen an article which gave methods for preventing it like this.  Second does anyone know of any other articles regarding this subject?  Also what if the front and rear waves come in contact before they get to your ear, at a point where the rear wave has not gone three times the distance of the front wave, but by the time each wave hits your ear the rear wave has gone three times the distance of the front wave.  I ask this because I am planning to have my subs firing forward, with the port for each one right next to it. 

The main problem in designing an enclosure for this theory is making the rear wave travel three times the distance of the front wave.  The subs are located in the trunk, and I am not willing to use all of my trunk space on this enclosure.  The subs and the ports will be the same distance from the listening point, so this means that the distance that the rear wave must travel inside of my trunk must be two times the distnace from the port to the listening point.   So my plan was to design an enclosure which has a series of channels inside of it to provide more distance for the wave to travel before it is released out through the port.  The only problem with this is that the enclosure is only going to be about 1.75 cu ft..  So I don't have that much air space to make a bunch of channels.  Since the port is just an opening smaller than the mass of air being pushed, which creates pressure and manipulates the sound coming from the subwoofer, making the channels inside of the enclosure smaller than the size of the cone would essetially make the channel one big port, and I don't want to do that.  But I don't have enough air space to work with the make channels that big, so heres the idea that I had.  Make the channels on the outside of the port.  If I made the channels larger than the port, would the channels have any influence on the sound?  Below is a picture that I made which diagrams what I'm asking.  This seems like a solution which would leave the airspace inside of my enclosure where I want it, by adding a channel on the outside.  Basically what I would like to know is will this channel effect the sound at all if i make it bigger than the port, or will it act like a really long port?

Sorry, I guess I forgot to post the link to that article.  Here it is... http://www.caraudiomag.com/technical/0203cae_box2/ 

and for some reason my picture didn't show up.  Another question I had was why do standing enclosures in home audio have channels running through them?

And as far as cancellation not occuring inside of a vehicle, this article contridicts that, unless I'm reading it wrong.  Even if cancellation does not exist, can anyone answer my questions anyway?  And I've read that is you have two subs facing each other, like each at opposite sides of a trunk facing inward for example, that they will cancel each other out?  Is this not true either?