Overspeeding has negative safety and economic effects. Also, in trying to beat time by speeding excessively, the driver might end up having more travel time.
The best way to react when bonnet flies open when driving is to think fast, watch around you within split seconds and brake. There are also thing to do to prevent its occurrence.
Where there is no way to fix an overheating car on the spot, these are information needed to be able to drive an overheating car to a workshop or safe place.