My mom gets scared when I am driving. I don't drive fast (I'm not crazy), usually well below 100 Kmph, yet the way she is scared of how people at times over take from such a close distance, or people crossing the road when you're at a hight speed, so she gets scared, that makes me uneasy too. I too get scared with her.
That's why I don't feel comfortable. Walid sahab on the other hand used to be a side-seat driver. Now he isn't because we have separated cars, but if I have to drive while he is with me, I feel very uneasy.