As weird as this sounds, when going through arsen investigation classes, one of the things to look for is potatoe chips ( doritos, cheese puffs etc) as they were used to start many car fires for insurance fraud. Bad guys would place them under the seat of the car, start one of the chips (puffs on fire), walk away. They would be long out of the area when the bag of chips caught the seat on fire and all the cops would find is a bag of inocent potatoe chips. Insurance payed big money till they caught on. Truth is strange. EPI