In the midst of doing all these jobs on my Turbo - the air duct was in dire need of replacement due to corrosion of the metal reinforcement.
Just to help future readers of this thread the duct itself is standard 60mm reinforced air ducting, I got a metre of neoprene duct from ebay for just shy of £10
https://www.ebay.co.uk/itm/JJC-Single-L ... 1267732535And then you want a couple of 55-70mm jubilee style hose clips to finish the job off.
EDIT: and if you want a cheap source of Voltage Regulators you just need a 14.5V 28mm mount version - BERU GER 004 is the one to get.
Picked up again for less than £10 from the Green Spark Plug company (no affiliation)
https://www.gsparkplug.com/beru-ger004- ... -0811.htmlI think it is robbery that there are some so called "Porsche Parts Specialists" that get mentioned on here from time to time selling this part for 4 x the price.