fortunately you have snapped the pictures of Cars from either desi community around you or from expatriate residential locations. , they consider SIN of removing any decal / sticker from the car when purchased new from dealerships.
The data about engine & its efficiency is pasted from inside over the new cars is mandatory (by law) in KSA, just like in USA. There is nothing abnormal to it, keeping it pasted after purchase is the show-off mindset almost every expat have, they want to show people back home for very long and it seems abnormal.
i know one person in KSA @memad who got brand new Land Cruiser and protected the pasted shipping details of his vehicle over the front windscreen under rear view mirror for over an year.
91 RON sure is high efficiency petrol and lately SHELL & PSO started selling it in Pakistan Too.