Here's this shot redone completely from the original raw files. The cloud looks a little different because I layered the pano pics a little differently than I did last time. I took out the terrible color cast, since I assigned each picture to a 6300K color temp and added no color correction in Photoshop. Is this, even more of an improvement? The first has the most post-production (a little contrast, saturation, levels, and dodging and burning), the middle is a conservitive pp (a little contrast, saturation, and levels), and the third is the RAW files stitched and nothing else.
These are a definite improvement, especially the middle image. The main problems I see are
1) The white balance is way off— use the eye dropper tool to set grey balance on the white stripe on the road in PS or LR. If you want that green/gold color shift back that you lost in setting white balance, it is easily achievable using the Channel Mixer... in PS (keep overall percentages for RGB close to 100%) or the Split Toning feature in LR;
2) No part of any of these images comes close to pure white or pure black. Correct this by using Levels... in PS, hold down Alt and drag the rightmost slider to the left until some part of the image shows white, then hold Alt and drag the leftmost slider to the right until something in the image shows black. Drag the center slider to normalize brightness.
This should give you a good starting point for further tweaking. I still feel that the image is missing a subject, though. Any chance one of the images you used to blend this shows the car a bit larger in the frame?