I use maps mainly but the TOmTom is useful when near the destination in a strange location.
Its mounted in centre-ish area on windscree ans powered from a socket i fitted just forward of passenger door and up under the scuttle. Power from a spare connection that is a non-permanent output i.e. only live when ignition is on.
As for the voice.
MMMMMMMMMM
Joanna Lumley.....
I love it when at journey's end..
" You have arrived at your destination, darling"
I sometimes break the journey to stages to get the effect!