I really like the choice of background, it's a nice setting, and the style of mods you have gone for are good too. I'd like to see you do the chop in a higher resolution next time. Generally 1600x1200 is ideal for advanced choppers, or 1280x1024 for newer choppers. It may be harder to find donor images in the higher resolution, but the effort and time spent is well worth it because the whole image turns out much better.
Rims are good, I just think there is one thing you can do to improve them. I see that they have too much blue hue in them at the moment. What I'd like to see you do is (on a new layer) paint some of that brown (sampled from the background somewhere) over the top of the rims, then change this layers blending mode (perhaps 'hue' blending mode would work best here). You may need to lower the opacity of that layer down a tad also (50%), but I think overall it will help to make the rims look like they belong in that scenery better. It makes the colour of the light on the rims match correctly.
Also sometimes I like to add a slight dark shadow under the wheel arches (i.e. make the shadow go over the top of the tyre a little bit). I feel this helps sometimes too.
Keep it up and keep on practicing! The old saying of practice makes perfect couldn't apply more for chopping.