Symmetry.
That's about it.
If the rest of the motorsports world can manage to get both sides of the car looking ok and reading correctly - why can't the Drifting/Tuner fraternity manage it?
I've always thought the US flag looked funny when backwards on the side of an airplane and wondered why they don't turn it around. As for the mirror writing, it seems that they have very unadvanced brains and thus use it as an encryption and can't come up with a petter "code."
The flag backwards on the side of a plane simulates a ship's ensign, viewed from the starboard side. If it was hanging from a pole, that's the direction it would fly in the wind as the aircraft travels. I've seen uniformed services doing that on the right sleeve as well.