other than some of the bugs you mentioned (refuel bar doesn't move, car is kinda slow to accelerate, transmission is weird) it works fine! the car gets you from point A to point B and it's way easier to handle on the dirt roads than the Ferndale. i hope you continue to work on it!
Specifically in this mod a manual gearbox is also impossible.
Why could install? For luxury. In one country is very common to install components from bmw to Volga's and other soviet cars.