Question: "i noticed mould growing in the boot of my car. Upon further inspection found the spare wheel compartment was full of water."
Answer: The seals around the real lights are prone to leak, as are the air vents hidden behind the back bumper. We have even known cars which only leak while driving along because water spray comes up from the road and finds a hole. There are many areas which can cause a leak into the boot of the car, but it's the mould which is most concern. It releases mould spores, which can make you quite sick if you breathe enough of them in. This is why every car which comes to us is first treated with anti-microbial.