Must get somebody to show me the trick of those drains sometime. Never touched them in 4 years. Had no bother, probably because most of that time it was either inside or had a half cover on.
The linked video is pretty good, he highlights two different methods to clean the filters, the one I’d recommend starts at 6:47
The drains themselves are a separate topic and covered in the video below.
Have just managed to take mine off and clean them, after 6 years they were pretty well blocked, washed the foam insert as well.
Only problem (apart from the contortions required to get to them!) Is that the the little push tab that releases the clip that holds them in broke when I pushed them to release the filter. Luckily I noticed before I replaced them and trimmed off the plastic wedge that should clip them in as they would have been impossible to remove again!
Anyone had this problem? Will they stay in place without the wee clip?
Do I need to buy replacements?
I also had the same problem, as the plastic is brittle in cold weather. I bought a new one from Mazda to replace the broken one. As suggested here, either do the job in summer or warm up the clips using a hair dryer. If they stay in place without the clip I would put them back in place until you can get to replace them with new ones.
I put the old ones back and will get some replacements for the warmer weather as you say!