The series you are referring to is the Town Car "Signature L." It is the top-of-the-line Town Car. It starts at $50,500. This Town Car is extended, I think about 8 inches, in the rear seat. These are the options available:
Select a package or options.
PACKAGES
Rear Seat Amenities Package
[+]
N/C
OPTIONS
Trunk Organizer (Provides Flat Load Floor)
[+]
$195.00
High-intensity Discharge (HID) Headlamps
[+]
$495.00
DVD-based Navigation System with THX® Certified Audio System (Not Available in Alaska or Hawaii)
[+]
$2,995.00
Six-Disc In-Dash CD Changer
[+]
N/C
Audiophile® Dual Media Sound System
[+]
N/C
17" 10-Spoke Machined Aluminum Wheel
[+]
N/C
17" 18-Spoke Chromed Wheel
[+]
$895.00
P225/60Rx17 All-Season BSW Tires javascript:__doPostBack('ctl00$ContentPlaceHolder1$grdViewOptions$ctl07$cmdExpand','')
N/C
P225/60Rx17 All-Season WSW Tires
[+]
$125.00
The ones with "check marks" are standard on the Signature L.
The Curb weight on the Signature L model is 4,518.
**Keep in mind, moonroofs are not available on this car, but heated rear seats are standard.**
http://www.lincoln.com/towncar/models.asp