Did you know you can set regular hours for your car’s availability (or unavailability)?
I didn’t!
I sometimes have to pick up a child from school on a Friday night, and last week the car was booked just a few hours before I had intended to use it. Thankfully I got it sorted, but it reminded me to be more careful with my own bookings when I know I will need the car 
I mainly use the mobile app, and as far as I know you can only block the car for the full day which is a shame if you only need the car for an hour or so, so hadn’t bothered in this case. Oops!
I just happened to come across the ‘calendar’ function on the website the other day, and thought I’d mention it in case others hadn’t found it.
If you go to your car’s ‘calendar’ on the website (not app), you can not only make a personal ‘reservation’ for a specific day and time, but if you scroll down, you can block out specific hours on particular days if you know you use it regularly (which I don’t).
I thought I’d mention this in case you too had missed it. or if you were considering signing up and were concerned.