Talking about mistakes ... forgot to install this part! Was not on the AROCS drawings I got, but is needed anyway because it holds the bumper stops for the hook mechanism.
Had to remove the sub frame to be able to install it. Too frustrating trying to get the bolt in there with sub frame attached to the main frame. Instructions call for M2 x 8 philips ... seems a bit long to me, but can always file it down later.
Good thing I caught in now. Here it is in place:
And the lot back together again. You can see how the narrowing main frame made it practically impossible to install it unless one has infinitive patience.