Regardless of speed, when hitting and knocking over trees, walls, and the like there is an extremely high chance of damaging the engine so badly that it breaks completely and need to field repair. With out any previous damage I have knocked over walls at a range of speeds as low as 10 kmph up to max speed and destroyed the engine. I am pretty sure the engine is in the front so I kind of understand why it could breakdown but the frequency of this happening seems so high considering the armor on the Panther. On top of this I have not had this happen in any other tank, even the Cheetah (which I believe has the same body as the Panther). There is no reason, that I can see, why the Panther should be immobilized by walls an Ifrit, Hunter, or Strider can plow right through at even higher speeds so I assumed this could be a bug or error. I grabbed a quick video of this but it is hard to do it in an uncontrolled environment where tanks and helis are not firing at me so I can only provide this short clip at the moment. This may be intentional but after asking around no one seemed to know if it was. I concluded this is a bug but perhaps I should be requesting a feature change to the game (I am not entirely sure with my lack on information).
Honestly not sure what priority this should be... after reading some other reports I moved it to normal as it does effect the viability of a vehicle.