More Colors:

Move the cursor out of the painting area.  Now press and hold L1+L2+R1+R2+Select.  An RGB Option appears on the side of the drawing board. Move to a color, and press R1+Up or Down to change the values of the color.

Mirror Mode:

Choose a race and hold L1+R1+Select+Start until the race begins

Rotate Logo:

After you've imput the more color mode, go to paint menu, hold L1+R1 and then press any direction to flip your artwork, you'll be able to put it on the car the way you flipped it.

Toggle Rear View Mirror:

To turn the mirror off, press Start then hold Triangle, while holding it, press L1, and the mirror will go away.  To get the mirror back, keep holding the triangle and hit R1.