Can anyone advise where I can get a replacement 058103221 Vent hose for 1999 V reg A4?
Stopped making 01/10/2016, without replacement

 

Any of these look like the part you need? audi 058103221 | eBay

 

That's the part I need for my ADR & APT engines, it's for the 'Non Turbo' 1.8 motors.
Unfortunately I ordered (4x) 058103221E , which is a different hose that does the same job, on a Turbo version...

So make sure you order the 058103221H version. I see it can be ordered from Poland cheaply. Considering you could order a few & sell them on.
The USA market dosn't use the 1.8 nonturbo version so it's sorta hard to get anywhere but in Europe. & Expensive elsewhere.
I did adapt a hose & used a 90° pipe bend, but I'd rather have the original hose.
Take into account that there should be a rubber diaphragm one way valve in the plastic inlet ducting it's attached to.
And at the other end, the plastic gooseneck will need to be replaced & the housing it fits into will be needed to be cleaned.
It's easier to just unscrews the cap screws & remove this whole unit, than to remove the gooseneck fitting itself.

I'm wondering if I should go for the Turbo version rocker cover. That way instead of crankcase ventilation being just 'Suck + blow' from the crankcase. I could have ' Suck' at the crankcase & 'Blow' at the camshaft cover. Giving it airflow thru the engine.