Hi, can anyone help me with a query, how would two deaf people communicate while driving in a car?

This is my homework for my BSL Level 2 course! Unfortunately, even though I am learning BSL I don't actually have any contact (at the moment) with any one who is deaf or hard of hearing.

I work with children with specific learning difficulties at primary school level and would like to progress to a primary school with both hearing and deaf children eventually and use my bsl.
