My thread still lives...
My update is that I did indeed get a Sat Nav for christmas, a Garwin. It was on offer at Halfords, and I'm delighted with it.
I've had a few fee-paying bookings at unfamiliar locations both outside and inside Leicestershire since I got it, & I have to say that it was absolute bliss to not have to look at a map, write it all down, and cast anxious glances at it all the time whilst driving and get there SO easily - and ON TIME. Just banged in the post code, and followed what the sat nav told/showed me. I've got several more bookings to come over Easter and the May bank holidays as well as the wedding season in Summer and autumn. It is a relief to not have to bother with maps and not worry about getting there late or stressed from the journey due to uncertainties about the route and taking wrong turnings etc.