This is not bad at all i love the reflections ,but ther are some issuesm i guess you had some debt of field on your camera ? as the rear part is blurry, try and do this also with backplate, as the scenery is sharper then the car, then realism really gets broken.
Also the left side of car has white reflection but the scenery has orange and red , should look if you hdri is not facing the correct angle ?:
The wheels again are odd sidewall has camber ? its like a RC car i have it my self on mine haha but wheels chrome is great .
You have some overbright / sharpness issue with headlights, not sure if there might be an exposure issue maybe,
I like the kit its a great design a bit wide for my liking but its great look.,
Also door has no refelection from the ground or the grate ? ilooks a bit odd.
Im only telling you this so you can get better not to hate <3 hope you understand I need to be picky as I my self get this everyday now haha great job mate overall keep at it! =D
also good luck with corona! its soo good, I only know Arnold,cycles, and Vray, but i dont have 3dsmax or CInema so i cant use cronoa but its a good tool its hard to learn I have heard but looks like your learning fast =D