R33's have a double latched setup from factory... you could pull the bonnet release cable at 200kph and it wouldn't fly open... Of course you're more than welcome to make your own additional restraint with a carrabeana and a loop of wire to secure it further. Edit: I would be running the additional if I had an aftermarket bonnet, carbon fibre, bracing removed, or something like that which could allow the bonnet to flex more than normal