rear drainage pipes in the sunroof mines does the same as yours when pparked facing up hill watergathers in the recess of the sun roof and pours in. get a long piece of thick wire and poke it down the tubes till it stops if it comes out the back end of the tube inside the boot its not that thats blocked if it dont then it probably is and ya should try and un block it. iv just never got round to doing mine so i park it facing down hill all the time lol
