Weird Squeeky Sound (Solved)

Almost three years of ownership and 41.500Km on clock my Roomster developed a slight squeeky sound every time she was starting to move from stationary. To give you a better image of the sound I can describe it like the sound you can hear from worn front bushes. Or like rubbing two pieces of rubber to each other. Or like an old sofa bed.

After an thorough check I found that the noise came from the boot area. It was generated by the boot's floor carpet and especially the cardboard that she is attached on. This cardboard rubbs itself at the top of the spare wheel's styrofoam like frame - housing - case you name it.

I soved this by spraying WD40 on a paper towel and then applying at the cardboard. No squeeking sound on acceleration again.