hey! I agree what Mark says... To have a realistic scene like you want to have ..you need to fake the sun with light(s)... ever seen two suns? (the word suns doesn't even exicts :p) You probably want every angle well lit so....the way I would adjust your scene is get rid of your 2nd light and replace it for some lights at 0.1 volume... ...just make sure you won't get 2 shadows...(you might wanne play with the main shadow aswell
)
cheers
btw... nice bike
