I confess to being a bit of a Doctor Who fan... But I'm not really a fan of Catherine Tate, so I'm happy to see Martha back for a few episodes :) iei!
I never liked Sat Nav anyway... It always got me (well, the person driving) hopelessly lost in Tokyo.
(And if you haven't seen this weeks Doctor Who episode, then what I say will make no sense what-so-ever... No worries...just beware of your 'alien' Sat Nav.... haha)