I've done a really quick 30 second job to show you more the sort of thing you should be aiming for. It's certainly not perfect, but if you compare to what you have now, you will see the difference.
->Brushed with low opacity light blue over the upper surfaces of the paint, this becomes your 'sky' reflection.
->Darkened lower areas on the side, but left a light bit at the bottom, this bit is the reflection from the ground
->Made the rear wheel less eliptical
Hope this helps