Not wishing to trawl through all the 89 recent posts on this subject
could I ask a question I asked once before.

Is there a Sat Nav available that allows one to examine the suggested
route, and modify it if necessary, ON A COMPUTER SCREEN, and then
upload it to the machine ?

Yes I know they mostly will allow this on their own screens but their
screens are generally too small and the resolution too poor for them
to be of any use.

Paul Mc Cann