… Have a tendency to silt up. Then the brown rust monster strikes mercilessly. And because we have been able to continue driving with the current, more than six months long, wet but brine-free autumn, the drainage happening now, before spring breaks loose, is more topical than ever.
Sliding roofs must be able to drain. And with some hassle with a compressor and tubes, it is possible to arrange something.
But a purely mechanical solution often works better. That solution is such an 4 mm thick nylon wire as used to pull electricity through pipes in walls.
That stuff is thin, but sturdy enough to be pushed through the drainpipe. Blowing with compressed air is then only necessary to blow the pipes clean and empty. And if the nylon thread unexpectedly comes under the back seat, then you are at the beginning of a new, challenging job ...
Consult your local Gamma or Praxis
Oh yes: also check if the air intake and residence for the windscreen wiper motor have not changed into a swamp full of composting leaves.