The sound of the car under throttle can be heard at a few points and it has a wonderfully deep growl. We'd guess it's the V8, if pressed. Porsche recently told the world that the Panamera we've been seeing in spy photos (and videos) isn't necessarily the final form, perhaps deflecting some criticism of the rather awkward shape. A production version isn't expected to be unveiled until the 2009 Geneva Motor Show, so there will likely be a lot of changes between now and then.
Video clip after the jump.
Thanks for reminding us about this, Serge!
[Source: MotorAuthority via Auto Play]