In 2003 all of the Arrows A23 chassis and the full Arrows Grand Prix International intellectual property rights were bought by Minardi. The Arrows A23 was renamed the Minardi PS04 and in back-to-back tests, it was found superior to the Minardi’s PS03.
Minardi, however, decides that they could not run a “pure-Arrows” and hence used the Arrows intellectual property, which included the new designs for the Arrows A24 and the best elements from the PS03 and PS04 / Arrows A23 to develop the Minardi PS04B for the 2004 season.
Following the demise of Arrows, the A23 chassis and intellectual property rights to them were bought by Paul Stoddart, then the head of the Minardi team, as a potential replacement for his own team’s PS03 chassis. The chassis was renamed the Minardi PS04, although it was largely unchanged from its condition as raced in the 2002 season.
A comparison test next to Minardi’s PS03 chassis proved it to be largely on the same level of performance as the PS03 but with worse reliability. Thus the decision was made to modify the PS03 for the 2004 season, resulting in the PS04B chassis.