Anybody attempt to build and new rubber/silicone/clamp hose system to replace the corrugated plastic breather lines? I was thinking about putting something together. Any thoughts or advice?

 

I would throw my 2 cents in, since I may the only one in a long time to post something related to the breather lines.
Although I had the locking ring at one end of the bank 2's hose broken ever since I bought the car, I kept it and Jerry-rigged it. I believe they're constructed of plastic for a reason - the oil vapors don't stick to the line's walls as much as compared to a rubber hose. It is just my own supposition, but it may hold some truth to it - I have no idea.
On the other hand, I believe the lines have a pretty good internal diameter (opening) for the vapors to circulate unobstructed, so why bother?

In any event, I did see a post/thread somewhere (Audizine? AudiWorld?) where someone did change the breather hoses to rubber ones.
You have a C5 and the exhaust recirculation is most likely different than mine, but I'm pretty sure there's no clear-cut replacement out there, unless someone came up with some silicone direct-fit pieces that might be better than the original setup.
On the other hand, I understand perfectly why you want to do it, since I personally didn't want to pay upwards of $ 90 just for a piece of plastic...
What you can do is peel/cut free the plastic breather hose's ends (so you keep the snap rings intact) and then you can fit'em into 1/2 inch diameter hose. A 1/2 inch hose slides also perfectly over the existent T in there, so no need to buy another one.
I have no idea how your setup looks like (or in a C5 for that matter), but you may need 1-2 reducers and 1-2 L-shaped elbows which you can find @ Ace Hardware. That's if you want to change most of the setup to rubber/silicone hosing.

 

My old hose is pretty brutal and I am going to buy a new plastic replacement for the time being. However, I will attempt the modification with the most appropriate rubber or silicone hose after I do a bit of research.

The snapping plastic clamps really scare me. It seems that they really don't seal the breather connections well at all. I was thinking of using hoses that overlap and use clamps on the outside of the relevant connections.

The plastic surely is less absorbent than any alternatives but the corrugation seems to promote the initial accumulation of build up. I absolutely could not believe the amount of gunk I discovered in these breather hoses the other day. Couldn't imagine any material could be any worse.

 

Did you fare better or worse than this?

 

You can replace the plastic section with vacuum hoses. (I saw a forum post a long time ago, but forget where it was.) Only thing to consider is that the hose section depth will be bigger than the plastic, so it would be a bit fatter, but I like mine a bit plump than skinny and brittle