Not sure where the holes are on yours, but they are normally at the front corners of the sun roof.
Open the s/roof fully, you will see holes either at the front corners or rear, maybe all four corners, model dependant, what I use is garden strimmer twine (thick one), cut yourself a decent length off (as high as the car) and with a lighter heat the end up and smooth it over so there's no sharp bits, get some warm soapy water and pour it in to the sunroof trough whilst threading the twine down the holes, move the twine up and down a few times ( don't be to aggressive), you should see water coming from under the car when clear.
VELVET BLUE UK INDIVIDUAL , IM THE LAST
UNITED WE STAND DIVIDED WE FALL
I stepped in a plate of Pasta the other day - now I have to worry about my Carbonara footprint!