Aren't these the same photos which surfaced a few years ago, when it was first said that the new trains would be coming? I distinctly remember the silver front car being shown on a pallet in a workshop and people saying how bland it looked.
The park have already tested the trains several times apparently, so can't see why they would still be stored like this.
In terms of speakers, I expect the trains will be based on the same molds as Speed of Sound at Walibi Holland. This has two speakers set back into the headrests to deliver the more detailed audio. There are then larger speakers under the seats/footwell in front if you if I remember rightly. You can see the ear-height speakers here, and can also make out the holes for them in the image Rob posted
It's actually a VERY effective system on Speed of Sound. The audio was crystal clear even for me, and you really feel the bass pumping through the seats. Of course, the epic soundtrack also helps
EDIT
Found the original link from 2013 with the pic
http://www.themeparkreview.com/forum/viewtopic.php?p=1360742