excursion and cabin pressure

SPL, as I understand it, will be a function of efficiency, displacement of the woofer, and power.  Excursion is only one component of displacement, the other being cone diameter.  Looking simply at excursion is a mistake, contrary to what Audiobahn marketing would like you to think. 

Displacement = cone diameter * excursion stroke.  However, most of the giant fat surround on a high excursion subwoofer isn't usable cone diameter.  So some "high excursion" subwoofers end up having fairly small actual cone diameter.  The high excursion ends up making up for lost cone diameter. 

A lot of those high excursion subwoofers end up sounding like ass and distort like crazy because of problems controlling the linearity of the driver.  In other words, don't buy your next sub based solely on excursion.  Also, remember to get that excursion you usually sacrifice efficiency and greatly increase the power you need.

If you are looking for high excursion I would look at subs with great excursion and low distortion.  I hear the Adire Brahma and the REAudio XXX subs are probably some of the best you can get in this category.

If that sub moves more in and out of the box then yes it will create more pressure (will you notice it inside the vehicle... depens on the sub, enclosure, car, ect..).  That sub is creating more pressure inside of the box because it is pushing against the box of air more.

My favorite everyday sub for max excursion is the JL 13w7.  A nice 1.5" of movement.  It's pricey but that is one of my fav's.  There are other's of course but I like the JL's since they can push some air while maintaining sound quality and stay in one piece.

I agree with kfr01 on RE and Adire for a high excursion sub with low distortion.