Hello there
Im definitely not a modder of CP2077, but i always wanted to drive with a mouse and figured out how to do it
BUT there are some problems that i can't solve by myself.
With this mod (rather options) you can turn your vehicle with mouse, BUT the sensitivity is VERY high AND the wheels can turn around for 360+ degree.
Please, help
Thank you.

https://www.youtube.com/watch?v=SL3mXAHH-Eg 
With vJoy it is able to make MouseX as LeftAxisX and try to drive with mouseX, while the game thinks it's gamepad
(you can try by your own, i got tired of this, but it DEFINITELY works, but need time to make sensitive perfect)
I'm leaving down my own controls that I like to use:

LeftMousButton - acceleration
RMB - deceleration
MouseButton5(SideMouseButton) - save speed

A(100%) and Q or A+W(70%) and W+Q(etc. 30%) turning degree
same for right side

I tried to ask CDPR, how to change sensitive in InputUserMappings, but there was no respond(
Feel free to continue my works, if you want to, my dear reader.

P.S. Know How
TO CHANGE BY YOURSELF

Cyberpunk2077/r6/config/InputContext
open it, find the text below and change it

<!-- VEHICLE DRIVE - used when player is mounted as driver and can control vehicle -->

<context name="VehicleDrive" >
<!--<include name="CameraMovement" /> --> 
<include name="VisionActions" />
<include name="UIExploration" />
<include name="PhotoMode" />
<include name="QuickLoadAndSave" />
<include name="Items" />
<include name="VehicleAuxillary" />
<action name="UseConsumable"map="UseConsumable_Button" />
<action name="Accelerate"map="Acceleration_Axis" />
<action name="Decelerate"map="Deceleration_Axis" />

<!-- ChangedStuff -->
<!--<action name="TurnX"map="LeftX_Axis_Vehicle" />-->
<action name="TurnX"map="MouseX" />
<!-- ChangedStuff -->

    <action name="LeanFB"map="LeftY_Axis_Vehicle" />
    <action name="RockFB"map="LeftY_Axis_Vehicle_RockFB" />
    <action name="ToggleVehCamera"map="VehicleCameraToggle" />
<action name="VehicleCameraInverse"map="VehicleCameraInverse_Button"/>
<action name="Exit"map="ExitVehicle_Button" />
<action name="CycleLights"map="Vehicle_CycleLights" />
<action name="Handbrake"map="Vehicle_Handbrake" />
<action name="ZoomIn"map="ZoomIn_Button"/>
<action name="ZoomOut"map="ZoomOut_Button"/>
</context>