I've used Cuvva a few times, and it's so quick and easy just to get insurance cover for a matter of hours. Even when we did get pulled over by the police when they were doing random checks one night, it all came through legitimately and we continued on our way.
I am fortunate enough to have not had to claim yet, but both my sister and I use it regularly to share driving on longer journeys and will continue to use it going forward.