From the look of that fire there wont be enough usefull forensic's to determine cause
I've had a near thing in a C4, catching it in time with resulting burnt hands.
I believe Bfit had a near thing with a C6 recently.
Both were electrical irrespective of the circumstances.
My experience with converted cars and what has been done to some of the electrical circuits and connections has been an eye opener.
But with no forensics, the real causes will stay hidden
