I have a fairly steep drive into which I normally reverse. However I popped out for 1/2 hour and got caught in a heavy rain storm. On returning to the car I noticed the rubber mat on the passenger side was a little wet, strange I thought. I drove home and as there was a car behind I pulled in nose up the drive. However I quickly realised that the water on the passenger mat was increasing and realised that the plenum chamber under the battery must be blocked. I rapidly turn the car round so it was nose down. I popped into the garage and grabbed a length of 10mm ID plastic hose, removed the battery cover and plunged the hose into the water and under the battery and syphoned out what appeared to be well over 2 litres of water. As I can not garage the car I am going to have to cover the lower screen and bonnet with heavy duty cling film for this evening as I can not get it in my garage. So guys be warned they do fill up when blocked and can do sever damage as there is one if not 2 ECU's under the passenger floor. Is it possible to gain access to the drain hole from underneath the car and rake out the debris. If so where exactly is it. Regards Peter