Yea, I can see that now, It is how it came from the factory.
I could try to seperate the Glass from the aluminum heat bed, though I fear I might bend it in the process. It looks like the MK3 ALU-Heatbed Dual Power frm the reprap Wiki, except it's 220x220mm.
If I can get the glass off without damaging the Heatbed I could also attach a magnetic PEI Plate to that, not sure if that thin alu plate is a good backing in that case.