Hi everyone. Sort of an accumulation of solutions to problems found on my 1.5 year-old K3.
(1) After searching high and low for about 1.5 years, I finally found the source of a plastic rattling noise in my K3. Initially I thought it was something rattling inside my steering (like a lose plastic vibrating in the steering) because the sound seemed to originate from there. Raising this issue to SC didn't help, as they couldn't replicate (or hear) it. It's the usual "leave your car with us for sometime for us to find it the source of the problem. Labour charges applies". Below is a video that I chanced upon, showing the exact noise that I had in my car (Problem 1: Rattling speaker grill at 0.:17):
https://www.youtube.com/watch?v=nVGpq8-PaNA-I pried open the tweeter speaker grille (locked by plastic clips).
http://www.kifomanual.com/speakers_removal-1315.html-Removed the 2 white clips and added some felt inside the plastic clips before clipping them back on. The felt prevents free-play when the white clips are inserted into the grille.
-Snap the speaker grille back into place.
-The annoying rattling noise seems to be gone for now.
(2) I've also mentioned some "cracking" sound from my dashboard whenever I go over humps on hot days back in 2016. It's basically plastic rubbing on plastic (plastic expansion due to heat). This sound got a bit worse over time and the SC noted the problem. Was suggested to "leave the car for a few days with us, labour charges applies...". "Disassembly and reassembly of the dashboard may not solve the problem, and may even make things worse, not really encouraged....best to live with it."
-I found an alternative solution, albeit not a permanent one. Apply silicone spray (got it at Mr. DIY) over the visible gaps on the dashboard. Spray and wipe immediately so that it doesn't stain other parts of the dashboard. Seems to quiet down the cracks quite a bit. But it may need reapplication after a few months. What to do...I can't live with the cracking noises.
(3) Also noticed some minor rattling sound coming from the A-pillar cover at the passenger side.
-Wedged some felt into the gap between the A-pillar cover and the dashboard. Seems to quiet down a bit, but still has noise from time to time.
(4) I've also tried the am-fm antenna mod mentioned by yorkhan in the forum (https://forum.lowyat.net/topic/2856023/+2840). Didn't seem to boost FM radio signal much for me though. Reception can be quite crappy from time to time.
http://www.kifomanual.com/antenna_inspection-1317.html(5) My fuel lid/cover gets stuck a lot. Quite frustrating - really miss the push-lid on the honda city.
-Eventually had to shave off some plastic off fuel lid so that the lid pops out properly. Works ok 95% of the time.
Hope this post helps someone eventually (maybe the SC too...).