TOPIC:

Today noticed a huge difference between my Kadjar and my friend's one. Mine is the red - 2WD, the other one is 4WD. Both 1,6 dci. Maybe it's not too obvious from the picture, but the white one has approximately 5 cm more space between the tire and the rear fender. I'm scratching my head what could be the cause of this, cause outer size of the tires is the same even if one is 17", and the other 19". Both cars have no modifications. The white is March 2017, the red is May 2017 (both at nearly 40K km). Any ideas guys?

A 4x4 will have more ground clearance to allow for off road driving.

According to the specifications, all models are the same height and ground clearance. Has either of you fitted different size tyres to the originals, and are the tyre pressures correct?
  https://www.renault.co.uk/vehicles/new-vehicles/kadjar/dimensions.html

Everything is stock. You cannot achieve 50 mm difference from tire pressure

just one thing, I dont think you should park them that close together, they will be popping out a Koleos 

there has to be a slight height dif in the 4x4 as it has a rear dif for one, as well as tighter springs for off road

Renault KADJARCompact car 4.1/5Carbuyer 4/5Auto Express RRP : From £19,525 Cargo volume : 472 L, 1,478 L with seat area Dimensions : 4,449 mm L x 1,836 mm W x 1,607-1,613 mm H Fuel economy : 47-66 mpg combined (38-58 city, 55-71 highway) Towing capacity : 1,350 to 1,500 kg
I would  think the difference in height in above specs is only because the Expression does not have the roof rails, other that  I have no idea, think Shredder's solution is  best one.