The standard flexi' "octopus" pipe that fits between the MAF and the turbo also has one "vent" pipe leading to the crankcase/breather and another one leading to the oil mist separator (the box underneath the airbox.. it sounds like yours fell off).
You could fit a straight pipe from the air cleaner, as long as the MAF sensor is still in the inlet path to the turbo.... but you would need to solve the problem of what to do with the two vent pipes.
The easiest way to do it is to leave the standard flexi' "octopus" where it is. The vent pipe attached to the crankcase/breather can stay where it is, as standard. You'll know that this works and it doesn't require any effort.
The other pipe, to the oil separator, needs to be attached to a closed system if you don't want to upset Greta or your vehicle tester. You could just stick a little cone filter on it.. and then strap it to the metal intercooler pipe (for example) with cable ties (somewhere where it won't collect water splash from the road)... but it must face downhill, so any oil can run out, and not back into the flexi/octopus.
But... having oil dripping out of this pipe might upset your vehicle tester. More and more tests these days don't allow any vehicle to drip oil, so check what the rules say in Czech Rep.
Having said that, the oil that collects in this pipe should be virtually zero, so you could stick a filter on it, tie it to the metal pipe and nobody will notice or care too much.
Don't cut the vent pipe to make it shorter. You could make a neat install by cutting the vent pipe near to the flexi/octopus and putting the filter on the end... but if it doesn't work, or the tester guy fails your car because it's venting to the atmosphere and/or dripping oil, it's rather expensive to find a new octopus.
Ralf S.
but I am afraid it can leak air. And since it is after MAF... Also I don't want to risk anything getting into turbo again. And when this oil box fell off, it pressed the tube on some hot pipe (intercooler input?), so it is damaged (not leaking yet). 
