Vector3 matrix multiplication

Hi unity fellows,

I find the Unity “mix” of transforms and matrix4x4 little bit confusing.
I have raycasted Vector3 that I would like to stick around with the collider/gameobject transform? How would you multiply Vector3 with transform?
This is usually done with Matrix multiplication, but now I can`t get it work with unitys set of functions.

Thanks,
-J

How would you multiply Vector3 with transform?

OR