[yon Beast]

The 2013 season will mark the introduction of the ‘Gen-6’ NASCAR racecar. At the heart of the new car is a desire to see more competitive racing by cars that closely resemble their showroom counterparts. Here are some of the key changes that fans will notice:
Distinct body lines that match street vehicles. The 5th generation car, known as the “Car of Tomorrow” featured a common template used by all manufacturers. During the development of the Gen-6 car, NASCAR worked closely with the manufacturers to design racecars that match their brands, while maintaining an overall car-form that keeps one from having an aerodynamic advantage over another. This is sure to reignite the passionate brand-loyalty (and rivalries) among fans that helps drive the popularity of the sport.

The “greenhouse” area is the same on every car. The area comprised of the roof, windshields, windows, and decklid is known as the ‘greenhouse’. In 2013, every car will have the same greenhouse shape in order to promote aerodynamic uniformity among manufacturers. Fans will notice different shapes and sizes of windows depending on the manufacturer represented, but the surface-area will remain consistent across the board.

Longer nose and shorter tail to mimic street cars. Fans will notice the longer nose (by 2 inches) and shorter tail (by 6 inches). The changes represent another move to make the cars more closely resemble modern production vehicles.

Carbon fiber hood and decklid. For years, teams have attempted to gain an aerodynamic advantage by making their hoods and decklids (trunk lids) flexible. At high speeds, these parts would cave-in and eliminate drag, allowing the car to cut through the air easier. Carbon fiber is very strong, which eliminates the opportunity for flexibility. This should remove the advantage some teams discovered and make it easier for NASCAR to police these parts. Carbon fiber is also light-weight which in turn lowers the center of gravity, helping cars find more mechanical grip and handle better.

New decals on windshield and roof. New decal rules will create a more personalized car that fans can more easily pick out of a pack. The driver’s name will now be displayed at the top of the windshield and the sponsor will be allowed to place a logo at the rear of the roof beside the number. To improve manufacturer branding, decals will no longer be permitted on the headlights and taillights.
Though there are many new features behind NASCAR’s Gen-6 car, it will remain one of the safest, most competitive, and easily recognized racecars in the history of motorsports. Once again, fans will be able to visit a dealer on Monday, and purchase a car that won on Sunday.

thanks Rich.
I looked it up.
These are the differences of which you speak...yes?

http://joegibbsracing.com/2012/11/28...scars-new-car/