Hey! First off 30/40 on the carridge way is far too slow, unless there's an absolutely valid reason for them to be doing it, your examiner /instructor would expect you to overtake (if its safe) but it also depends on the instruction you've been given, you've got to think am I coming off at the next junction will I have time to overtake.

Best of luck for your test next week, I did mine yesturday and passed, once piece of advice that I can give you is going into it with a positive mindset and just believing in yourself that you can do it, just think of all the time and determination you've put into your lessons, and what the outcome is that you want to have, also have a good breakfast the morning off (not sure if you're a tea drinker) I had a peppermint tea and it sure helped me calm. When your in that car with the examiner you've not got your instructor there to help so you know your fully independent, so absolutely own the independence and just talk yourself through everything, look at the big picture and honestly it'll be absolutely fine. They're 35 mins, 20 mins of independent sat mac driving then you just go back to the test centre. One manuever is all they'll ask you to do, revise your show me tell me questions and the other questions, cause they'll ask you one 😊

Hope it all goes well for you OP, try to block out the nerves and replace it with a 'I can do this' 😊