Very nice work. What makes it stand out to me is that nothing stands out, meaning it all looks like it belongs together. Very nice consistency all over, especially with the "dust". The exhaust can be that bright after just a few hours sitting still in a moderately humid environment, so if you like it, don't sweat it.
Your metallics are very nicely done but maybe a bit too monochromatic? You may want to work more on getting some contrast into those pieces on your next model since, as metallics, they tend to draw the eye. I am thinking specifically of the shovel blades and parts by the engine deck. Some differentiation of metal shades either with different metal colors or different washes should do it. Have some fun exploring how to do it.

But again, nice job.