I just found this manga today and I love it to bits.
I've always wanted a version of Detective Conan where Conan was more honest about his situation and it explored more of the consequences besides just being awkward. I really hope this has a happy ending for Subaru and Mio - they deserve it with all that they've had to give up.
If this becomes a tragedy, I'm liable to drown in my own tears.
I wonder if his initial avoidance of the car is some form of trauma regarding his "grandmother's" (mother's) death, seeing as they mentioned it was an accident (to which I am reading in "car accident", but it's possible it wasn't one)?