Thank you for the helpful observations and advice.
Let me respond to the last two in order..
1. I'm the co-driver/navigator and she won't listen to me at the best of times, least of all when I'm waving my arms around.
and
2. I'm the co-driver - it's the driver who needs the reversing camera!
Clearly there is some way to go (albeit not in reverse).
Cheers
Si