The term 'PART OF NASCAR' is composed of two crossword solutions, NATL (4 letters) and AUTO (4 letters). NATL stands for National Association for Stock Car AUTO Racing, which is the governing body of the sport of stock car racing in the United States and Canada. AUTO stands for automobile, which is the type of vehicle used in stock car racing. Therefore, the term 'PART OF NASCAR' refers to both the governing body and the type of vehicle used in the sport.