By Chloe Clougher

Copyright jalopnik

It will likely come as no surprise to learn that the gaping hole in your roof is a prime suspect when water appears in the cabin. By design, most sunroofs or moonroofs are not completely watertight. Instead, they have a thin channel built around the frame, which then guides rainwater into drainage tubes. These then typically run down the car’s pillars, and while this system works well when clean, the drainage tubes easily become clogged with dirt and leaves, which causes water to overflow the system and enter the cabin. Certain models are more affected than others, with certain Volvo models sporting an unusually complex design which frequently fails.

This can easily be tested by pouring a small amount of water into the sunroof channel. It should drain out through your wheel arch, or somewhere similar, but if you notice the water pooling or overflowing, you’ve found your culprit. A blast with compressed air, and maybe some help from a pipe cleaner, will usually clear the tubes out, although be prepared for old water and gunk to gush out during the process.

It’s also true that a lot of convertible cars face similar challenges. Even the best convertible cars ever made can suffer, especially if parked outside where leaves and other debris can enter the drainage holes, which are used to manage rainwater. Regularly checking and clearing these drains prevents leaks and extends the life of the roof fabric and the interior below.