Thanks all for the feedback.
As to why did I not just buy a car in the the US, trust me I am aware it would be easier. The truth is I would like to be able to do both: drive the same car on either side of the pond, and I figured it would be easier to buy there and take here than the other way around.
As to the legality, not trying to to break the law. I think I still can change my order to have only a rolling chassis imported and then get the engine from a third party, but by doing that I’m pretty sure I will not be able to take it back to my home country, when and if I go back there.
So for now it’s either ship it here as temporary import - I think 1 year or so - or nothing.