NASCAR's Competition Department distributes entry blanks for each race to owners in the series.
Those entries must be returned before the deadline, which is set 13 days in advance of the event.
When the entry is received by Competition, the car is added to the entry list.
There is an inspection fee for each entry.

Qualifying order is back to the old way, a randon draw. Someone from the team draws a bingo like ball just before the first practice of the event.

NASCAR Sprint Cup Series qualifying rules for 2013: (except Daytona 500)
1) Starting positions 1 through 36 determined by the fastest qualifying speeds in descending order with the fast qualifier being first.
2) Starting positions 37 through 42) will be provisional starting positions that were not among the fastest 36 from qualifying. Provisional starting positions will be assigned to the highest ranked NASCAR Sprint Cup Series Championship car owners who are present at the Event and have entered the Event by the entry deadline and will be assigned in descending order until the six (6) provisional spots are filled.
3) If positions 37 - 42 are not filled by eligible car owners, the remaining positions will be assigned to car owners based on qualifying results.
NOTE: Once provisional starting positions have been assigned, the cars will be placed in the starting lineup by their qualifying speed in descending order with the fastest qualifying speed starting thirty-seventh.
4) If after starting positions 1 through 42 are assigned and there remains a car owner whose driver is the current or a former NASCAR Sprint Cup Series champion who participated as a driver in the previous NASCAR Sprint Cup Series season and who was entered in the Event for that owner in that car prior to the entry deadline, a 43rd provisional starting position, the "Champion's Provisional", will be assigned to that car owner. The most recent NASCAR Sprint Cup Series Champion driver not previously qualifying for positions 1 through 42 will be assigned the position. 5) If the 43rd provisional starting position is not filled by an eligible NASCAR Sprint Cup Series champion, it will be assigned to the next highest ranked car owner based on the NASCAR Sprint Cup Series Championship car owner points.
6) If any starting positions remain unfilled, they will be assigned according to current calendar year NASCAR Sprint Cup Series Championship car owner point standings.
7) If any starting positions remain unfilled, they will be assigned to the car owners who have made the greatest number of qualifying attempts during the current season.
8) If any starting positions remain unfilled, they will be assigned to cars in order (1,2,3&etc.) in which their numbers were selected in the qualifying draw.
NOTE: Until the completion of three races of the current NASCAR Sprint Cup Series season, the final previous season NASCAR Sprint Cup Series Championship car owner point standings will be used for determining the starting positions for the highest ranked car owners as described above.

If practice and qualifying are cancelled [rain, etc], the following procedure is used:
1) For the first three races of the current season the top 36 teams in the previous season owner points would make the race [team doesn't have to had run all the races in that season]. After the first three races of the current season, the top 36 teams in the current season owners points, would make the race.
2) Then any winning driver or team owner from 2012 or 2013, as well as any past champions, make the field.
3) Then, for the first three races of the current season, any of the top 36 teams in owner points for this year would make the field.
4) Then it goes to qualifying attempts this year, with ties broken by owner points.

If first practice is run, but qualifying is unable to take place, the starting lineup will be based on speeds from the car's fastest lap from the first practice, with top-36 in speeds placed in that order. The next six cars use provisionals with the highest on owners points (previous season first three races, starting race 4, current season owners points), not already in the race via speed getting a spot. Then the those six cars are lined up by fastest speed in practice. The 43rd spot is for a past champion to use, if needed. If not, the next team eligible for a provisional gets the spot.

More info on Past Champions Provisonal and rules and limits on my 2013 Past Champions Provisional Page