Dock-

I agree completely! My Car is about the same internal size as a Journey and I did not realize how good the stock system was until I tried to improve upon it- My first "go round" of aftermarket hardware with basic 10" enclosed sub, basic amp, nice receiver (CDA 117) and what I thought were good comps (Alpine SPR 60C) actually sounder WORSE THAN FACTORY!
Of course, key to this was the fact that I did not amplify the rear door speakers.

I could not get the Car to sound right without the rear speakers in the mix- it went to hell without them like your experience in the journey. the car's interior volume and acoustics are the reason- and the fact that the rear doors are much better bass enclosures than the front ones are.
I wouldn't know what to do to tune the system for front speakers only. At this point I don't see why I would want to- my car sounds great as it is.
The time alignment really helped.