[jeff_kovalik]

A driver can enter different categories at the same event with different vehicles, but never the same car in two.

Race Procedures, Section 2, Page 3

QUALIFYING
To constitute an official qualifying attempt, all vehicles must selfstart
and self-stage. At NHRA Mission Foods Drag Racing Series,
Lucas Oil Drag Racing Series, NHRA National Open, and Summit
Racing Series Finals events, a contestant cannot drive more than
one vehicle in the same category at the same event, nor can one
vehicle be used for multiple entries. Multiple driver restriction for E.T.
classes, at NHRA member track events, may vary based on specific
member track E.T. regulations. Racers are advised to contact the
respective division office or member track for regulations within
that geographic area. Vehicles must remain in the same category
entered, with one registered driver for the duration of the event.