Is there any way to open back of cargo plane?

[Cimlah]

I don't know how to open back of cargo plane with possibility of placing there cars like in Just Cause 3. Is there any mod or something?

[Frozium]

Unfortunately the Crago Plane cannot be opened by any means and I haven't seen any mod to do that so far... The only way you could transport a vehicle with it is by grappling it (which unless you have an unbreakable garpple mod it's gonna be quite the task).
Other than the Zhejiang 6903 (the ferry) or any flat truck (and only works for light vehicles), no vehicle can transport another without grappling.