PROBABLY, he knows all the tells! Although frankly, he respects it - he can't really hide his own limbs particularly effectively, and this does make his life harder!

anyway he has like no reason to be in a mechanic's shop, not owning a car and being perfectly capable of his own repairs in any case, but since they live in the same city they could probably run into each other easily enough! Otto's pretty fucking noticeable when he's out and about.