Hi Marco Polo,
What I'm saying is that any form of exchange is hindered because there are these problems: too many loopholes for illegal immigrants, ghettos, violence.
In my view, most illegal immigrants youth don't even care about their own culture and use it as a mere pretext to go counter-culture against the Native Europeans - for the sake of being different, for being criminals.
If you look at the more educated realms, this exchange happens: and there actually is no really relevant distinction between "Native Europeans" and "New Europeans", except for the skin color and other features of appearance.
Not a melting pot, but rather an osmosis pot.