Inspired by Niko's DIY polarizer for the SG9665GC and the discussion that followed in this thread - https://dashcamtalk.com/forum/threads/magnetic-cpl-lens-filter-for-street-guardian-sg9665gc.10942/ - I decided to try doing something with items I had laying around the house and that would work for both my SG9665GC and A118-C. More importantly it had to be cheap and easy. Being as how my favorite non-permanent fastener is Velcro tape I wanted to use it, especially since I have a lot of it around. Next was the polarizer itself - not something most people have laying around (I do but all my 35mm lens filters are much too large and much too expensive to donate to this project). In a flash of 'genius' (stimulated no doubt by my going outside and putting my sunglasses on) I decided to sacrifice a pair of clip-on sunglasses, a relatively cheap solution if you don't already have a pair laying around and need to go buy one. I figured if it worked as eyeware it should work on the dash cam as well. Here's the sunglasses I used - after hacking it up. Cut the lens to roughly the shape of the lens housing - a decent pair of household scissors is more than adequate for the job. I wasn't sure if top/bottom orientation made a difference so I cut it straight on the top and with a bit of a curve on the bottom so I could mount it on the camera the same way they would be on my eyeglasses. Affix Velcro along the sides in the rear - Next I cut some (very) small pieces of the matching Velcro to attach the lens to the camera, ...and put them on the camera. It's then just a matter of sticking the polarizer on the camera. I had initially used a strip of industrial strength Velcro along the edge but it was too thick and caused vignetting so I took it off and replaced it with the small pieces of household Velcro and that took care of the issue. Now, after all this the big question - Does It Work? Yes, but not without some issues. A118-C (rear camera) without (top) and with (bottom)- It does a pretty good job of removing reflections in the center of the glass but not so much at the bottom. I have the A118-C installed as a rear cam and with the slope of the window it's positioned so that the sun hits it pretty much all the time. The vehicle has a light colored interior and cargo cover so reflections were quite bad because of that. Also notice that the polarizer was a bit dusty and had some spots on it that really show up when the sun hit the lens directly. It will be necessary to keep it pretty clean. Also, having the sun hit it directly causes a 'sun spot' to show up in the video - the only solution to this is to not drive in the sun but then reflections wouldn't be an issue either. SG9665GC without (top) and with (bottom) - I don't have the 'GC' mounted on the windshield (windscreen), it's on the underside of the rain sensor housing, so it's a bit protected from direct sunlight so in this example no dust is showing. One of the concerns I had is how this would affect night performance of the cameras since the sunglass lens material is pretty dark. I haven't had an opportunity to drive after dark yet but we do have some very long lighted underpasses that might substitute. SG9665GC functioned pretty well - A118-C not so well (keep in mind that the rear of my vehicle has some pretty dark privacy glass so this is NOT an accurate side-by-side comparison - it may perform better in front) Finally here's a video clip driving through the underpasses - SG9665GC followed by A118-C. It's pretty obvious that A118-C really struggled with the combination of dark environment, dark filter and dark privacy glass. Edit: Just for a point of comparison I put an SG9665GC with the filter in the rear to see how is would handle the dark glass and a filter. Here's the video. It's obvious that it works much better than the A118-C. Conclusion - It's a cheap (no cost to me since I had everything on hand - $10 for enough material to do at least 4 cameras if you had to buy everything) and easy (I could do a camera in 10 minutes or less now that I've got it figured out) solution. I've decided to not use it on the A118-c rear cam, at least for the time being, because the benefit doesn't outweigh the downside I expect with night time performance. I'll keep it on the 'GC' at least until I test it in actual night driving conditions and see how it works out then. Even if it turns out that night performance is unacceptable it's easy enough to just pull the filter off the camera and put it back on the next morning. Another piece of Velcro on the side of the camera could be used to store the filter and keep it from getting lost when not in use. The A118-C would probably do better in low-light as a front camera vs. in the rear with privacy glass. Performance would be better with both cameras if I could find a pair of sunglasses with lighter lenses than the ones I used.