Boxer Diesel sudden power failure

Hello to each other, as new Subaru Impreza XV diesel driver (EZ 12.2011) I have to turn to the forum with a bigger problem: from Km approx. 1600 the following sporadic error occurred, the distances between the errors became shorter and shorter: – vehicle breaks strong acceleration from lower rotation range (from about 1500 revolutions, forward 2+3 gear) at approx. 2000 revolutions abruptly – vehicle returns to approx. 1200 revolutions, gas is no longer possible – after gear change l or clutch tread very easy acceleration possible again – at higher speeds (e.g. switch back to 4th gear, can be detected sometimes heavy blow) – engine temperature without meaning (partly with blue temp light, partly also after 20 km drive) – possibly switched off completely (green lights off) – range Diesel-Kat no indication After already several very dangerous situations (in crossing area Bundesstrasse no Lei 60 km/h had to be aborted, behind man almost had to be driven up, excavator 25 km/h could hardly be overtaken) was brought equipment to dealer. Pickup with km -Stand 3200: – update played – error not reproducible – error did not occur at test drive Nowmore since km Stand 3700 comes error again. (up to 500 km three times occurred) Had someone already similar problems with the Boxer Diesel or can give me an error tip, since the dealer with the situation seems to be overfodert. more however at the moment lower problem: The seat mount of the Impreza is apparently overwhelmed with the power of the diesel –> Lean wiggles anyway, seat rail cracks in certain position at every braking or acceleration Thanks in advance for hints or tips a disappointed new-subaru driver