[notorious]

I wrote about it in the post where you took the picture from:

"It is possible to fix the hole without removing the box, you will need long tweezers, heat gun or hairdryer, methylated spirit or industrial adhesion promoter and high quality silicone or any industrial grade glue (Soudaflex is good stuff) in a cylindric cartridge, extra long nozzle for the cartridge, and a silicone applicator gun."

Edit: And you will need to remove plastic scuttle panel from windscreen to allow a bit of access, which is easy thing to do.