there are 3 drainage points, 1 either side under the scuttle panel and a pipe behind the engine in the middle, these get VERY gunked up so give these a clean out and it should be fine. as for the sunroof there is a little red clip on the handle, unclip this and just lift the sunroof out. run some water down the drainage tubes just to make sure they drain as they should, all going to plan that should be job done!