The design of the 2003 Williams FW25 was a marked departure over its predecessor, and was a completely new design compared to the Williams FW24, something that Williams had not done between 2001 and 2002.
The 2003 Williams FW25 design was a distinct change from its predecessor, being entirely new compared to the Williams FW24. This differed from Williams' typical practice of not introducing completely novel designs between 2001 and 2002.