From a press release issued by Yamaha:

Yamaha’s sleek new ‘R series styled’ YZR-M1 fairing made its public debut during the Suzuka IRTA test (March 30-31), one week prior to the commencement of the 2003 season opener, due to be held April 6. Riders Carlos Checa (Fortuna Yamaha Team) and Alex Barros (Gauloises Yamaha Team) sampled the aerodynamic package for the first time and came away full of praise for Yamaha’s efforts in making such a vast improvement.

The more aggressive and sharper design was born in the Yamaha factory after extensive wind tunnel and computer simulated tests. It features a much narrower frontal area, improvements to the unique M1 flexible air-intake system, and a hard-lined rear seat cowling.

Complementing the all-new aerodynamic package is a hand-made snub-nosed titanium exhaust system, which offers a useable power increase and 400gram weight saving over the original unit. With the one-into two muffler extending only as far as the rear swingarm unit wind drag has also been reduced further.

Although Barros and Checa are the first Yamaha riders to receive the updated components, making their competitive debut at the Suzuka MotoGP, Marco Melandri (Fortuna Yamaha Team) and Olivier Jacque (Gauloises Yamaha Team) will also benefit from both the fairing and exhaust system in the not too distant future.