Car fires happen to all makes.
There is an advisement by the NHTSA not to park your 5 series BMW in the garage due to an unsolved fire case. Imagine that.
It sucks and I can see why one wouldn't buy that brand again. But, I don't think its anything to worry about. Fires are investigated at very small population numbers because they can quickly cause life threatening damage if they spread to surrounding structures (the probability of getting hurt while driving a vehicle that lights off is almost nill)
Perform due diligence. After that, have fun. You worry too much and life will pass you by