Martin Truex Jr. was sent to the rear of the field ahead of Sunday's race in Texas after NASCAR officials confiscated the spoiler from his No. 19 Joe Gibbs Racing Toyota.
Two other vehicles -- the No. 49 of Chad Finchum and No. 96 of Daniel Suarez -- also failed prerace inspections and were moved to the back for the Autotrader EchoPark Automotive 500 at Texas Motor Speedway in Fort Worth.
Truex's No. 19 team also was fined $35,000 and docked 20 driver and owner points. Crew chief James Small also was ejected from the race.
Truex was originally sixth in the starting lineup and 31 points below the cutline for advancement into the NASCAR Cup Series' Championship 4.
According to NASCAR, Truex's team violated section 20.4.12.b in the rule book that states, except as specified, that spoilers must be used exactly as supplied from the manufacturer.
--Field Level Media