Good thought but a rental car would definitely not have road flares.

The general problem is that even if you're a well-prepared person in general when driving to remote locations--you're probably not (and can't easily be) well-prepared when flying to a foreign country and renting a car.

Heck, forget the foreign country part. I'd be a lot more prepared for somewhere like Death Valley if I drove there from the East than if I flew there and rented a car.

I think some countries require you to keep one in your car.