I have so many friends who have transitions. They like it.
My one friend said, she has her prescription sunglasses only as a 'back-up' and uses it only IF she will be outside in the sun ALL day. Other than that her transition lenses are just fine.
But yes, I have heard that in a car, it will not darken, nor as much.
My Mom, has those 'clip-on' type shades to go on/over her prescription glasses. Like flip tops. She likes it.
Then, she also has 'sunglasses' that fit OVER your entire glasses. It is plastic and it goes over your existing glasses as you wear them.
So, I was gonna get one too, either style. My Husband says "NO, only those Grannies/Grandpas wear those." (which in my State, does seem to be the case).
But I am getting Transition lenses. I finally decided.
I still have my prescription sunglasses though.
But I get SO tired of having to switch back and forth, between my regular glasses and my sunglasses. Constantly.
*My Optometrist said, they are NOT "sunglasses." They are transitional lenses. So if someone expects them to behave like sunglasses, they will be disappointed.