NASCAR investigating 'unacceptable' fires after Kevin Harvick's car went up in flames at first playoff race

NASCAR is investigating a spate of car fires that left one championship contender fuming after his Ford erupted into an inferno during the opening playoff race.

Kevin Harvick lashed out at NASCAR and the new Next Gen car after his inexplicably caught fire at Darlington Raceway. The Next Gen debuted this season and is a spec vehicle with single-source parts that is intended to both level the playing field and cut costs.

The Next Gen has achieved some of its goals but has also raised safety concerns unrelated to the fires involving the force of impact drivers are taking in crashes. Kurt Busch has been out with a concussion since late July.

Kevin Harvick's car bursts into flames! <a href=«https://twitter.com/hashtag/NASCARPlayoffs?src=hash&ref_src=» https:>#NASCARPlayoffs