Right - Jaime's choice of an xB wasn't necessarily for sound - he just liked the car.
For SQ, I'm optimistic that the roomy interior can be a benefit - but equally fearful of the nearly parallel glass walls on each side.
It does look like the windshield goes away from you quite a bit in front of the driver, which can be good...
...but thinking along those lines - the VW Beetle I still believe has some fantastic potential as a SQ vehicle, and most likely as an SPL vehicle as well (although no doubt still not as good as a classic VW Beetle was for SPL), although the VW Beetle is very much short on hatch space - I know from firsthand experience, my wife's had one for almost 4 years now.
I wish I could tell you firsthand how it is as an SQ vehicle - she won't let me touch the car, short of putting a set of wheels on it.
xB is a bargain, and a quality car - and probably not too short on balls if you get the 5-speed (automatic is against my religion anyway) -but it really does look to have a monster interior - good for SQ, bad for the big-bass cabin gain that smaller vehicles have.