[N.RotaryTech]

I'm looking for the interchangeability between s5 an s4 thermostat housings.
I searched a very little bit, didn't find much.

Anyway, as some of us know the plastic piece that's right on top of the thermostat on s5 N/A's isn't very reliable.

I found out this morning that mine is cracked an leaking. I believe it has been leaking for a few weeks. And In fear of it blowing (which I've heard and seen happen before) I wrapped it in electrical tape (which I've seen done an it works for a temporary fix..)

So I have 3 options, they also have an expense factor, I don't want to pay alot.
#1. Swap it with the one on my s4 N/A. (If that's interchangeable.) ($:Free)
#2. Get a new one from a parts store. ($: probably most expensive)
#3. Make one out of metal. ($:cheap)

So my first question is:
Are s5/s4 thermostat pieces interchangeable?
My second question is:
Which option should I do?, since this car is my daily driver, and I need it to run, and I want to get this done this weekend.