Hey everyone, just some feedback, I used electrical tape as advised, the knocking sound I used to get when reversing seems gone for now, not sure for how long. Then the main rattling noise I used to hear from the back when driving was indeed the Flap that covers the boot area, also took an advice from the forum, one guy used a Rubber Glove, it looked a little untidy so I used a Peg, separated it into two and put pieces in both sides of the Flap. I can guarantee that the rattling is gone.
As for the Adjustable Bumpers I couldn't figure out how to move them so I left them as is. I also tightened the bolts on the locker, this solved the fact that my boet was no longer closing Flush against the car and dust was building up as seen in the images. That problem is solved now. Thanx everyone.
Now on my to-do list, Faulty Parking Brakes, Increased Battery Drain, A Constant Beep that keeps going on it's own coming from the Engine Area when the car is parked and locked, beeps like 10 times, then silent, then again after say 5min, and lastly the front water drains unblocking before summer, I'll have to strip the car for this one.
See attached images.