One thing to note is that Beck also has a coolant overflow tank, as well, in the front of the car.
I had my coolant overflow in the back with the engine and I just put in a second tank that looks very much like what you have on the BECK except it is not under pressure but is plumbed from the overflow tank directly and correct the overflow and then allows the engine to suck it back into the coolant system. So far the results are very positive and my engine coolant has not gone down and I have not gotten any air bubble issue or need to bleed the coolant system. This season will be the big test.