In my case, the car is "a closet" that appears next to me in cities and at random encounters, I can interact with the machine just like with a container, I used the key, the speed of movement on the map has not increased, the character still walks on his own two feet, fuel is not consumed.
I installed LH according to your instructions, I didn't put anything extra.
That's it, looks good Your vehicle is just a moving container, you get no extra speed on WM or bonus stats. Fuel consumption is energy efficient, it takes a lot of time to see some fuel % change.