Phil,
Having been or lived in these places, I really like what you've done with both the composition and color with these images.
For the most part, these areas are rather drab by comparison to the images here, except when the light is right and then it can be magical.
Couple of comments:
1. On the greenery and the images with large spaces with red in them, I agree with the prior comments about the saturation - it's a bit much. However, I know the look you were going for and would suggest just a shade less from posted and you will be there. I've bought the Nik ColorFX3 package for NX2 and the Tonal Contrast filter really makes playing with curves much simpler and easier to get the pop you want.
2. I really like the Texaco gas station image. To me, that one is set right. I've taken to looking pretty close at image sets, depending on how many locations I shoot in and sometimes I end setting batch adjustments for each area separately. That may help you here as well, if you have quite a few to process.
3. These images are what the 18-200 was designed for. You are one of the few that is using this lens properly, IMO.
Good job...