There are 2 different lots of drains you need to ensure aren't blocked. Firstly the bulkhead drains
D3 Bulkhead drains
The good news is you can access them from below the vehicle if you can raise the vehicle high enough, the bad news is you will need a ramp, the good news is I have a ramp
I'm sure next you take your car in for an MOT and speak nicely to the examiner they will clean the pipes for you as it only takes a couple of minutes with a long screwdriver or similar tool to prod the crud out.
The good news is nothing needs to be removed to do this from underneath the vehicle. With the vehicle raised locate the gearbox mountings, then looking slightly towards the front of the vehicle on the transmission tunnel you should be able to see the pipes
This is the off-side
The near side looks easier to gain access, but the exhaust gets in the way so a long screwdriver was used to clear the rubbish out.
I then stuck the vacuum cleaner into the end of the pipes and sucked through any crap that was remaining.
After sorting out the bulkhead drains you need to check the Air-con evaporator drains
D3 air-con evaporator drains
These are accessed from behind the carpet at the gearbox tunnel. You will have to remove the foot rest on the driver side by removing the bolt cover and 8mm bolt, the footrest then slides upwards to disengage it from its fixing
Then just pull the carpet down a few inches to gain access to the drain tubes
The passenger side is even easier as there is no footrest. Access is however hampered slightly with some wiring so rather than risk snagging a cable I refitted the drain tube with a jubilee clip as access with the Clic-R clamp pliers was rather limited
