When the studio creates a windshield, backlite or fixed vent for a vehicle, there are certain parameters that are to be met, and their value assessed. Specific positions on a car will enable your creativity, others may inhibit it. For example a windshield requires glass, no latitude in material choice, but a fixed vent opens you up to polycarbonates (pc) if your budget can handle it.
As you conceptualize, ask yourself ‘Where does this vehicle fit into the product line up? Who is the target audience?” These questions are answered, globally at program charter, a particular up-front point in the program where management decides what this vehicle wants to be, but the designer needs to constantly ask him or herself, “am I pushing the envelope?, does it make sense to?” Function - aesthetics – cost - durability.
When I was at General Motors, we experimented with a ‘creased’ windshield in the Chevrolet SSR. The styling intent was to replicate the look of a 1940’s pickup.
The problem (there are many) with bending the glass that aggressively at the center line of the windshield it created a phenomena, similar to trying to look through an acrylic dowel rod. Everything in the driver’s line of sight became distorted. Telephone polls now appeared three metres wide. This definitely would have resulted in unmet expectations.
The fix was actually pretty easy and inexpensive. Generally there are no “class A” surface (everything visible to the consumer) changes after “styling freeze” but since there were no changes to the sheet metal or bright molding (chrome trim) at the header or windshield touchdown, a surface change to the glass was the only thing that needed to be modified.
By maintaining the styling theme at the header and lower edge of glass I was able to smooth out the windshield surface without affecting the attachment scheme or impeding program timing.
More books and blogs from Lyn R. Zbinden: Glass Engineering: Design Solutions for Automotive Applications: http://books.sae.org/r-433/,