Your car is private but you can't stop the cop from searching it,so I will suggest that we should try our possible best to memorize these words that are our seed phrase, some are twelve and some are twenty four,you can just start from one day and start reciting it,six words for a start till it becomes part of you and you move to the next six and so on. This is not applicable to people with various wallets.
But there are times when we are in a situation that requires us to bring our backup Seed Phrase. like we will move residence from one city to another. because I often do it for work reasons.
but hiding the 12 word seed phrase of our wallet isn't too hard on a journey. we can even write it on a small piece of paper and put it in the shell of the ballpoint pen we use. and put together ballpoint pens with other writing instruments. or many other ways.
after we arrive at our destination then we move the seed phrase back in the book or something like that and store it in a safe place.