Williams rookie Valtteri Bottas has revealed that the 2013 car will not feature a stepped nose.
2012 regulations meant that the majority opted to use a step between the chassis and nose of the car, with only McLaren and Marussia using a more conventional curve.
For 2013, a vanity panel is permitted, allowing teams to hide the step.
"As far as looks, the [FW35] car is pretty much as it was last year," Bottas told Finnish station MTV3.
"With the new rules, the step nose is straightened. That is the biggest difference in appearance. The new car is a development version of last year's. There are certain improvements in aerodynamics. We have tried to focus on getting more traction in corners."
Williams scored 76 points in 2012, including their first victory in eight years at the Spanish Grand Prix.
Bottas replaces Brazilian driver Bruno Senna, having taken part in fifteen practice sessions last year.