Car, girl, gun, a potent and classic combination of elements when put together make something that would appeal to most. The addition of a grainy texture (which I am noticing is something you commonly add in your work these days) gives a vintage and aged look to the design, which enhances the effect of the piece.

Drawing what you have here requires a pretty high level of mechanical and organic design. For Roza herself, I think you have knocked the ball out of the park, this is one of the most appealing OC's designs I've ever seen but more than that there is a considerable attention to detail regarding the fitting and design of her outfit. The only weakness that sticks out to me is how her hand is holding on to the gun.

Now as for that revolving rifle.... it couldve definitely benefited from the use of a reference. Specifically the rifle seems to be one big wooden forestock, when I assume its based off of a colt revolving rifle (nice choice) and should have a distinct metal barrel. As it is it looks like a toy pop gun.

As for the vehicle I feel like you wouldve benefited from having references of this car from multiple angles to better understand the forms involved because getting the perspective of this car correct is made into a herculean task from the forms of this car being organic coupled with the polished sheen of the paint job and glass. Parsing out what is going on exactly in the front as well as making it and the rest of the body in the proper persective while scaling it all to be in the correct propotions is ....well... even in the photograph it looks strange. The far headlight looks like its jutting out in front of the car, and that is exaggerated in your copy of it.

For your ambition alone I think you deserve 5 stars, but theres always room for improvement.