Chance, per the rulebook, changing colours and removing logos is fine, but reversing pictures is generally not accepted, since knowing if a car is LHD or RHD sometimes plays a part in identifying it. Just a friendly reminder. Keep the puzzles coming! 
Yes, here are the rules regarding pictures:
QUOTE
The following picture modifications are A-OK, and are considered by consensus to be acceptable.
1. Change color, or change to black-and-white or sepia tone.
2. Obscure or delete telltale background elements.
3. Obscure or delete badges, logos and number plates.
The following picture modifications are not OK, and are considered by consensus to be unacceptable and unsportsmanlike.
1. Replace design elements from one vehicle with those of another (wheels, grille, etc.)
2. Photoshop modifications that change the basic configuration of a car (change a coupe to a roadster; make a Tyrelll P34 a four-wheeled car, etc).
3. Photoshop modifications that place a vehicle in an incorrect time or place.
4. Reversing a picture to make an LHD vehicle appear RHD, or vice-versa.
UNQUOTE
So reversing a picture is OK provided it doesn't make an LHD car appear RHD or vice versa.
