"I heard somewhere that Ncap doesn't take into account colisions at different angles. Just headon and side. Therefore the results are not supposed to representative of what happens in most real world scenarios. "
NCAP does the offset test at 40mph. That my friends, is a very tough test to pass as only one side of the front/structure absorbs the impact. Good design means the energy forces are distributed equally over the cars safety cage.
It is impossible/expensive to replicate every type of accident collision/different angle, so NCAP simulates the most common and the most structurally demanding - which is the front offset test at 40mph.
It does the side impact at 30mph, too and a pole test.
While the 147 did badly, you may find it does better in real life - NCAP cannot compare Alfa 147 colliding with VW Golf, or Astra, or 3-Series. Cars' front crumple zones are at different heights, which almost makes a mockery of NCAP. For instance, the Megane has good NCAP, the A3 has average NCAP. Collide them together at 40mph offset into each other, and the results are very, very different...