EV with ac motor?

Hello you there,
Just found this forum, another, I am looking for some information about re-winding an ac 3 phases motor. So i found this page and i have been supprise to see, or, it is looking that ac motors are not used very often in electric vehicule. I understand in bicycle but in car?
I'm not in EV at the moment but i had a project few years ago with a nephew, but we never pursue it, but always interested in learning and i dont understand why there is not more of them...
Any way what i m trying to do is to rewind an existing motor with twice the amount of poles to reduced it speed in half.
I already imagine all kind of reaction, but i m a big boy i can handle.
Thank's in advance it is going to be fun, right