I phoned BA, and after being given the run around with their telephone system options not being clear, I was told to select the option of "I booked using Avios", despite using cash...

I got through to the Avios Group team, and they said that I would have to cancel the car reservation, rebook it and pay a £30 cancellation fee. I asked them, what if I booked a separate day, could BA/Avios link them together? They said no, they couldn't and I would have to speak to Avis to see if they would combine it.

Does anyone have any experience with this? Does anyone know if Avis will link 2 separate BA/Avios Group reservations? I will of course ask Avis and see if that's something that they can do.