As a person staying in the East, going to Volkswagen Centre Singapore is such a hassle. I decided to see what I can do about the problem. After examining the side mirror, I found a gap on it (refer to picture below), which could be the access to the folding mechanism. My intuition tells me that the noise could be generated from the folding mechanism and decided to spray some WD-40 through the gap. Bingo!, the squeaky sound is eliminated. A re-application is almost certain in the future after the lubricant dries off. But it is not a difficult process anyway.
Here are some interesting facts about the WD-40. It was developed in 1953 by Norm Larsen, founder of the Rocket Chemical Company, San Diego, California. It was originally designed to repel water and prevent corrosion and later was found to have numerous household uses. WD-40 stands for "Water Displacement – 40th Attempt". Larsen was attempting to concoct a formula to prevent corrosion in nuclear missiles, by displacing the standing water that causes it. He claims he arrived at a successful formula on his 40th attempt.