 After a race, the top 5 finishers, one other random car, and the first car failing to finish the race not due to an accident will have their cars inspected.The winner, random car, and first car out also have their cars and engines taken by NASCAR for further inspection at the NASCAR Research and Development Center.Further, there is one random race per year where NASCAR confiscates 15-20 engines and takes them to NASCAR's Research and Development Center for evaluation, comparison, and to help decide on future rule changes.