If you ever removed those covers, you absolutely have to reseal them. It's glossed over in the diy tutorials for replacing the struts. I think once upon a time the seal would hold up, but on my 2006 that seal completely disintegrated when I removed the covers. I think I was the first person in there in 14 years. I cleaned them the covers and roof with goo gone / rubbing alcohol and used a healthy bead of loctite marine sealant.I am guessing my issue has more to do with the drain holes. I noticed VW used butyl(hate that stuff) to seal the covers over the strut chambers. I am thinking I need to seal that better since I opened them and clean drains. The water drip off tail gate wont make a fish pond out your spare tire well, its just annoying.