The concept is for a local run around, not extended trips or holding on to the vehicle when your not driving it.
Once your milage allowance runs out (40 miles IRC) the charges start to ramp up pretty quickly. The excess included on the standard insurance is also high, so extra charge (£100 PA) to cover that too.
Also you have to check that a prevoius driver has not damaged the vehicle without reporting it, which you could then be held liable for. Some people don’t clean up after themselves, don’t bring the vehicle back on time or leave only fumes in the tank
The charges have steadily increased and the branding has become much more obvious and garish since being bought out.
A great idea, it’s just flawed by the introduction of customers and people having different standards of what is acceptable.