If you want a nice system that adjusts for teams having multiple cars; then simply add up all the points that the cars in a team accrued and divide by the number of cars in the team.
Stewart-Hass divides by 4.
Penske divides by 3.
Ganassi divides by 2.
Richard Petty Motorsports divides by 1.
Formula 1 for instance, just adds up all the points accrued by the cars in a team for the Constructor's Championship. It might have produced a situation where three were 3 cars in the points, way long ago in the past.
I think the way he means is how NASCAR does it, as NR2003 is mainly a NASCAR sim. In this case each entry accumulates points individually on an entry by entry basis, regardless of driver. THis means while Mark Martin finished 27th in points, the #01 finished 17th in points. It also catogorizes the #01, #1, #8 #13, #14, #15, and #39 as all seperate entity's, despite them all being part of the same team/s(#01, #13, #14, and #39 for Ginn Racing, then the #01 went to DEI, while the #14's points became the #15's)