Nice job with the blending. If you want to touch things up, I'd suggest adding some contrast. Make the dark areas (vents and undershadow) darker and touch up some reflections and up-ward facing objects with an eraser. Also sharpen up your pencil and go over some of the car's lines, like around the lights and I'm sure the hood has some lines on it, as well around the greenhouse.
If you want to change the original, do those things, it would look a lot crisper, sharper and nicer.