Simonpolly - you can still access tools OK with sub in place. If you need to actually take out spare wheel you need to lift sub out. It is no different to lifting out a box though. One very simple cable to unclip and the. Lift it out
REDHP - at the level I have the base there is very little vibration. Golfs are so well hung together that in the few weeks I have it in there, I have not noticed any rattles or vibrations developing. Don't get my wrong, this is still powerful enough to get the car shaking , but I just wanted a good, solid base tone without the horrible flat distortion you get from standard stereo.
The one thing I will say is that is does make your rear view mirror shake. Makes it difficult to see perfectly behind you. I never really worried too much about that anyway

For me this did exactly what I wanted. 100% satisfied.
Any more questions, happy to answer.
Here's a photo of the plug you need to unclip to remove the sub.
