Awesome design.. but here's your answer to why it fails and looks like a toy:
[img]You've completely changed the perspective of the rear arch, almost doubling the gap for the wheel in its width.
On the base, the distance between front and rear wheel was, as usual, 3.5 times the width of the wheel....
On yours... it's only twice the distance
A similar problem is true with the front wheel
It's a mistake i used to make when designing concept cars on paper - the car wouldn't be long enough...