hey polini,
i have no doubt on your camera control as it's done properly
your first piece of photo with teh pickup datsun is preetuy impressive because i admire teh colour corrections that is done to it.
but you have to improve your ocmpositions skill and your creative /art sense .
i'm sure you'll be albe to do that..spend some time looing at some other people photo's about cars...tyhey have very stunning dynamics in their pictures whereby yours are flat.
and regarding your watermark....don;t do it that way..spoils one eye to look enjoy it. put it big enuff outside the image.