The Windshield
 

There are two types of windshields available.  The 02, 03, and early 04s had the heated wiper rest feature for use in cold weather - turns on when the temperature is below aa certain point so the wipers will not be frozen to the windshield.  This feature was eliminated for 05s.  Do watch that you get the windshield that goes with your year of t-bird.  The wiper rest windshields appear to cost more to replace than the windshields without the feature.
Operation of heated wiper rest is on page 39 of the 2002 owners manual - in the climate control section.
 

Electric window heaters (heated wiper rest) — Located at the base of the windshield, this feature heats the front glass area below the area heated by the front defroster where the windshield wipers sit in their parked position. When activated, the feature keeps the wiper blades warm and reduces the chance of ice build up on the blades. The indicator will light when the feature is in operation. With the ignition in RUN and the engine running, the feature will be automatically enabled if the temperature is below 5°C (40°F). The feature can be manually selected or deselected at any time. However, the automatic feature will be enabled each time the engine is started. In cold, dry conditions where wet snow or ice is not present it is acceptable to manually deselect the operation of this feature. The feature will run continuously unless a low battery condition is detected, or unless the feature is manually deselected, and will only activate when the vehicle engine is running (to prevent excessive drain of the vehicle battery).

The shortened version is due to the fact that the center dash controls changed for the 03s (and later) and the heated wiper rest button was eliminated.
There is no mention of the heated wiper rest in the 04/05 owners' manuals.  However,  an early 2004 electrical manuel shows it for the '04s and some owners have tested their own and found that they do have the heated wiper park.  Apparently there was a change in December 2003 and later 04s came without.  The 05's DO NOT have heated wiper park.  This is important to know when getting your windshield replaced.  An installer should know the difference when they take out the old windshield.

The original style logo/markings look like this:

There is an extensive discussion about replacing cracked windshields on this thread on TBN which includes the following conversation a member had.

An owner contacted Carlite directly, regarding the OEM windshield available for his PCR (04 Pacific Coast Roadster special edition), and got a quick and authoritative response from their Technical Services Manager.

Here it goes:

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If your vehicle has the heated wiper park feature, you will need a DW01546 GBNCAR. If your T'Bird doesn't have this feature, then you should get DW01559 GBNCAR. We indeed carry the OE parts with the OE trademarks. You will need to insist on the Carlite parts in order to get the original. Even though these windshields are made by PPG, they are not allowed to sell the parts with the Thunderbird logo through their aftermarket channels - they can only sell them to Carlite who then distributes them to the aftermarket.

Rod Watson
Carlite Technical Services Mgr.
rwatson at ach-llc.com

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The following article is still available on the internet from the original source:

from: http://www.glasslinks.com/newsinfo/tbird_2002.htm
PPG Designs Windshield for 2002 Ford Thunderbird

 The windshield in the 2002 Thunderbird is the most complex in the industry, says supplier PPG. The bend is 27 mm vs. the typical 8-12 mm. The angle of installation is 24 degrees vs. the traditional 30 degrees.

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The story of the T-Bird reincarnation is filled with engineering successes big and small. The design team worked with vendors to devise the most complex windshield in the industry, and developed elegantly simple solutions to such pesky problems as coefficient of drag, body stiffness, and noise, vibration, and harshness (NVH).

Engineers wanted a steep angle for the windshield to cut down on top-down turbulence. Also, the Thunderbird windshield is the first to combine an extreme depth of bend and an A-pillar wraparound. Those features give it the most complex geometry of any windshield in the auto industry, according to PPG, the glass supplier that designed it.

The Thunderbird engineering team specified a windshield bend of 27 millimeters instead of the typical bend of 8-to-12 millimeters. "Getting that bend and wrapping the windshield around the 64-degree-angle A pillars was like wrapping a sheet of paper around an orange," says Tom Kerr, PPG's general manager for OEM automotive glass.

Additionally, the angle of installation Ford wanted to cut down wind turbulence—24 degrees to horizontal vs. the traditional 30 degrees—made the optics more difficult and placed the wiper blades in a position more forward than accessible by the defroster.

Then, there was the matter of the antenna: Ford wanted it embedded in the windshield to, among other things, prevent snagging on the top during installation or removal, and to reduce the wind noise from whistling that can occur with outside-mounted antennas.

Using its own home-grown computer models in conjunction with I-DEAS and exchanging files electronically with Ford, PPG engineers modeled the windshield shape, highlighting the area around the A pillar. "We had to know if drivers could adequately see through the windshield or whether they would be looking at fun house glass," says Kerr. Working together in real time, PPG and Ford engineers adjusted the shape slightly to get the required visibility.
 
 

source: Press Release: I-DEAS from EDS PLM Solutions

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