The Prius, although extremely clean, reflections included, with it's perfect body lines and a very good wheel blur, feels a bit strange, really. Seems like there's too much of the car in the picture, and as that is a car without any 'focus point', the eye looks for another point of interest. And that's where it fails, since there isn't one. The well executed blurred ground is not meant to grab attention and the background is almost non existant. So, the problem was never the quality of your work as a photoshopper, which is excellent and well visible on this image, it was more of the shot itself as an image that grabbed attention. 👍
The Supra felles extremely realistic for me, I love the light in it, the overall color of the car. Body lines look awesome, in perfect proportion to the car (not easy, the car's small in that shot).
Did you clean the rear panels? They look really smooth. Also I like the composition of this shot.
Only thing not quite working for me is the blur on the scenery. The pole (sorry, can't remember another word for it
) is right next to the car and is blurred, whereas the fence and bushes way past the car are in focus, some of them below a blurred tree.
Also, ground texture is very well applied, looks great. But it suffers from the same 'blur problem', since it's blurred on the left and right, despite being at the same camera distance.
The MR2 shot has great colors (you seem do always do great shot at this location). That car is usually great to work with, since it's extremely well textured almost all over, I really like the reflection you caught just under the rear wing.
Again, body lines seem perfect to me, those rims actually look great on that car, and the texture on the ground looks even better on this shot. Are you just applying it straight or distorting it to match perspective?
Anyway, I hope I didn't 'sounded' too much of a nitpicker, since all the not-great things I mentioned about the Supra shot are minor things, really. Most of them I only noticed after looking really hard, and like you said, the main goal was about the lighting and body lines, and as far as that, you nailed it!