Multiple namespaces for an Engine

Disclaimer: i’m fairly new to Rails and I don’t know whether this would
be
desired behavior.

I want to make an Engine that is isolated by two namespaces. That is,
let
say for example I’d like to make an Engine whose classes all live in:

Car::BMW

And thus, my models for example should be placed in:

app/models/car/bmw/

And my tables should be prefixed by for example:

car_bmw_

I tried to accomplish this by having this code in lib/car/bmw/engine.rb

module Car
module BMW
class Engine < ::Rails::Engine
isolate_namespace Car::BMW # This will call: engine_name ‘car_bmw’
end
endend

With this code whenever I generate a model however, the model is placed
in:

app/models/car

And the table is prefixed by:

car_

The reason for this can be quickly seen if we look at
Rails::Generators::NamedBase.namespaced_path which is defined as

def namespaced_path
@namespaced_path ||= namespace.name.split("::").map {|m| m.underscore
}[0]end

Shouldn’t it be possible two have your models and controllers be
namespaced
by multiple namespaces?