Stichting Club Alfa Romeo Bezitters

and couldn´t find it in my literature ( repiar books and parts list). So I asked an Alfa master mechanic who had never seen a spring in that location before.
There´s a rubber cap on top of the rear transaxle holding the bottom of the spring in place and a metal plate giving it hold on the top.
All parts are italian made ( reading BREV. bologna) and seem to be professionally made for the car.
The only function I could imagine is , that the spring is an additional part for higher trunk load (maybe for LPG tank which had been installed once)
I removed the spring which was working easily and got an additional rear drop of about 2 cm`s ( Eibach lowering springs and Koni yellows installed , rear always looked "pumped up" before removing the spring of mystery.....)

So my question is: Can anyone tell me the real function of this spring construction???

I think you already told yhe function We call that 'helpingspring' IS mostly used to compensate extra load, such as caravans or LPG tanks.
But you can also use them if you think the car handles better this way, or for better comfort, etc.

It's an original feature, have had 2 cars with this extra spring

Thanks a lot for your answers!
I will leave the spring uninstalled , because it lifted the rear of the car and was working against the lowering springs. But now I can besure that there´s nothing wrong with the car!