BIS released P3D model files are ODOL format which is optimized MLOD (not decrypted, do not even say that) and cannot be opened with O2, you need to use one of these two following tools;
Mikero's ConvertP3D which in fact while writing this page doesn't work that good.
T_D's P3DDeBinarizer which works nicely.
Also P3D Analyzer.
However before you use these tools on OA models, you need to hex edit the P3D's because their version number is higher than the tools are looking for. This is bit more complex but doable.
Open the P3D file in hex editor of your liking, you can see the ASCII part which says “ODOL2”, scroll cursor to the ODOL2 part and change that to 1, so the ASCII part would read then “ODOL1” instead. Save the P3D and then the current tools will open it fine.
Unfortunately at the time writing this page ConvertP3D or P3DDeBinarizer will NOT work on BAF and few selected OA (upgraded on v1.54 patch) P3D model files.