The exterior sounds are pretty interesting. If only I could use it for the interior with some minor fixes for immersion.
The cabin output, sounds more like a recording from a badly miked source. They could have used a wind sock on the mike to help preserve other more important sounds instead of drowning it out with bass overloaded wind noise.
I am certain that the ears will hear something different from a recorded product as its an art to reproduce sounds with high fidelity.
The engine backfiring sounds would certainly be audible from the cabin although muffled. I can't hear it from the cabin in this version. I know the creator wants to keep it "pure" and that is respectable, but it would be good to have the option to have a sound of what the human ear would hear sitting inside the cabin instead of what sounds like a bad recording. Its not completely bad though. It just needs refining.