By 2003 Papyrus had spent nearly a decade iterating on stock car physics, track accuracy, and online infrastructure through a succession of NASCAR titles. NASCAR Racing 2003 Season represented the studio's accumulated expertise: the physics engine was refined under direct consultation with NASCAR team engineers, marking one of the first documented instances of professional motorsport engineering input in a consumer racing simulator. The game included all 23 Winston Cup series tracks scheduled for the 2003 season and 42 anticipated Winston Cup teams, with the notable exception of Chip Ganassi Racing entries.
Players could choose from testing sessions, single-race events, a full championship season, and multiplayer. Car setup options were extensive and reflected actual stock car engineering parameters. Three months after launch, in May 2003, Papyrus published a free downloadable content pack containing three fictional tracks — an unusual move for the era that extended competitive play. The game notably included Dave Blaney, a driver absent from EA Sports' rival NASCAR Thunder 2004.
In March 2004, EA Sports activated its exclusive NASCAR licence, and NR2003 was pulled from retail shelves. Papyrus Design Group was shut down by parent company Sierra On-Line in May 2004, ending a seventeen-year run during which the studio had created the most critically respected line of motorsport simulations in PC gaming. Sierra's own servers, which had supported the game's online racing, were taken down in 2007.
David Kaemmer, one of Papyrus's founders and the lead programmer on IndyCar Racing and multiple NASCAR titles, purchased the NR2003 source code and assets for his new company, FIRST LLC. That codebase became the technical and philosophical starting point for iRacing, the subscription-based online racing service launched in 2008, which went on to become the dominant platform for professional and semi-professional sim racing.
NR2003 received generally favourable reviews, with Metacritic aggregating positive critical consensus. PC Gamer US awarded it the 2003 Best Racing Game prize; reviewer Andy Mahood wrote that it "established a daunting new standard for PC racing simulations that may take years to eclipse." According to Edge, the game sold at least 100,000 units in the United States, though it was outpaced by the earlier NASCAR Racing 4's 260,000 domestic sales. Total US sales of Papyrus NASCAR games released in the 2000s reached 900,000 units by August 2006.
The game retains an active modding community decades after its commercial discontinuation. Community-built mods have added cars from Formula One, IndyCar, sports car racing, and other disciplines, running on NR2003's physics engine and on circuits recreated to modern accuracy standards. This persistent community activity is unusual for a title of its era and reflects both the quality of the underlying simulation and the gap left by its removal from the market. Within the sim racing community, NR2003 is regularly cited as one of the greatest — and most consequential — racing simulations ever published.