Let's start with an exploded view.  Our man Charlie did some perfect, factory technician in training style teardown of this interior.  We didn't have the front seats completely out, but trust that the factory center console removal and reinstallation is likely 8 hours in a flat rate book!  The rear seats, with some practice could easily be removed in about 2 hours.  Then reinstalled in another 2 hours.  This car was labor intensive.  Handcrafted Italian elegance is cool until you try to take it apart.  Hand assembled, premium materials, high quality leather.  You can't just let a monkey loose in here!  Charlie, even on energy drinks, is a methodical dude in these interiors.

Carl got down in the trunk area.  Carl and I encouraged Greg to lose the spare if we really wanted to retain all of his trunk space.  Now the sweet challenge was how to build a proper box for a Hertz HX250 subwoofer in a proper, sealed configuration with a sturdy box with a provision for the Audison LRX5.1k amplifier.  DOOD!!!  And the parking brake mechanism had to provide some air volume and depth for the sub, so the box is a combination of 3/4" MDF wood and fiberglass, sturdy and braced.  This car now rocks!

Here's the fully constructed and wrapped subwoofer enclosure and amp rack.  Carl then built a cover for this area and Tony cut some acrylic in the shape of the Maserati logo. 

 So now, the trunk floor looks like before except for the raised Maserati logo in the floor.  This same floor panel features a large area of steel mesh to allow the subwoofer to freely "breathe" through the panel.  (I've also uploaded a video to YouTube, search for "Maserati stereo upgrade"!)

Here's a nice shot of the side of Greg's car.  This is one sweet looking and sounding machine.  I mean the exhaust as well as the stereo.

And the front, of course, with that wicked looking trident.  This is the shape we mimicked on the trunk floor with some custom carpet wrapping work.

This is the interior from just the rear seat area.  Yowza!

Here's a shot of the sub enclosure and amp rack that Carl built.  He put some angles on the box so it wouldn't look boring or ordinary, and I think he achieved something sweet and fitting for this car.

And one final parting shot of Greg's beautiful car.  Thank you Greg for being so patient.  It was I, Rod, who was cocky and assumed we had some traditional speaker layout in the front end of this car, the doors looked like they housed a midwoofer, 6.5" or so, and everything else seemed straight-forward-with the exception of it being a really high end car and requiring more time and work compared to just about any vehicle Asian or domestic.  It turned out that the doors didn't have a speaker at all, but the clever folks at brand "B" speaker/amp company decided that 3.5" speakers in the dash and a single ported subwoofer on the passenger floorboard are all this car really needed for the front speakers.  This was a challenge, but creatively met with some pillar mounted Hertz MLK tweeters, an HL70 mid in the dash location, then we finally capped that off with a demo Focal 5WS 5" sub in the factory "brand B" ported enclosure.  The rear doors got a set of Hertz MLK165's with some sturdy mounts and clean wiring work, an Audison Bit One with Ipod input, tuning, tweaking and dialing in the system initially (Carl does this part) and this car sounds really really really good.  Thank you Greg for being so patient.  We took an entire week of exploratory inventory of speaker locations, options, and debating tactics and ideas to really make a system work well in this car.  This is only the second Maserati we've worked on, and we've found that Ferrari's are actually easier!  I'll get those videos uploaded to Youtube asap, search for car audio innovations.