Porsche 944 Rear Knocking Noise

I recently found my Porsche 944 had developed a knocking noise coming from the rear of the car when driving over bumps and uneven surfaces so had the car jacked up to investigate. I checked all the suspension components, the shock absorbers, the anti roll bar and the various mounts for gearbox and rear axle. Nothing appeared to be amiss and I couldn't find any components that were loose or could be touching together to make any noises or sounds from the car.

Porsche 944 Rear Knocking Noise

After checking underneath the car I had the tailgate open to replace the toolkit and realised that I'd not looked at the spare tyre. Lifting the carpet I noticed that the bolt holding the spare wheel to the bodywork was loose meaning the wheel could move every time there was movement in the car. 

After tightening this back up the noise has gone and the problem of the knocking sound in the car has been solved.