Just sharing an experience and disclaimer, I have bought and sold a few car parks in the last year and half (judge me all you want, but when you can't beat them in HK.... join them LOL)
Two years ago after getting scammed by an Australian company "guaranteeing rental returns on boutique art pieces", decided to stick to good old HK tried and true investments.... piece of paper record showing property ownership... But as I was not flush to buy actual apartments and I already own a village house (joint named with my wife which people told me was stupid as it locks both of us into the one home ownership) so other properties would be taxed heavier, I had to think of other ideas. Not posh enough for properties back in Canada either and don't want properties where I don't know anyone who can physically reach within an hour.... so....?
Then I thought what about car parking? Well, everything on HK island was also out of my price range but I saw tons of ones for under 400k HKD back at the end of 2016. I looked at ones that carried existing rental contracts and thought the returns were decent so at least it was better than holding worthless pieces of doodle paper (sorry if anyone's an artist here but my experience with the art scene in HK from that scam has not been kind on my views of people in the industry).
So I bought one in Tsum Tsang and one in Sheung Shui with existing rental contract and forgot about them for 6 months. To my surprise when I checked the asking prices online again, the one in Tsum Tsang had doubled. I'm like no... must be just fake listings.... but looking at transaction records, it showed it really was going up. When I asked the agent who handled the purchase, apparently Chinachem was going to release more parking (they owned the whole car park since early 2000s) up for sale starting at prices that were doubled from what I paid. I held onto that until end of 2017 and also sold the one in Sheung Shui that didn't double but made a decent appreciation. Then I was like heck why not.... and bought another one in Shek Kong for under 400k (and the transaction records show if I had bought in end of 2016, they were also only 280k each). Even before I completed the month long wait for the final payments, my agent called me and said "Yes or no, my buyer wants to buy it for 480" and I was like make 110k in 2 weeks, why not??? Now they're being listed for 580k.... Since then I've decided to just buy and hold for a couple of years to see what happens.
But of course I saw there are risks. When I Googled more in depth the name of the estate car park in Tsum Tsang after I bought it in 2016, I was LOL FFFFF when there were Chinese news articles about how people in 2010 couldn't find any renters and had to rent it our for like 300 HKD a month or leave it empty. But since then car ownership has gone way up in the New Territories where people assume they need a car to live there (that trend could disappear once the MTR expands their network to cover more and more of NT and also companies starts having their offices more in Kowloon and not just exclusively island side).
Had a chat with the owner of one of the units I bought recently and was enlightening.... explains to me finally how I see all these people in HK that appears like they don't need to work. She says there's "house wife groups" who pools their funds and goes and buys up 30-90 car park units at estates to bump up their prices and then flip it and move onto the next estate until they've raised NT car park prices to Kowloon levels LOL when I went to pay the management fee once, the lady in line in front of me was there to pay for fees on 8 car parks and she looks like the typical c-lai not a posh CEO LOL
Don't really agree with the way things like this skews economies... but when you can't beat them....
Edit: but I think the game will be over in a year or less as there are no longer parking for sale under 500k in the NT, most are coming up to 700-800k. Even motorcycle parking is being speculated into 300k prices.... I think there will come a saturation point.... but then people have been saying that about residential property in HK for a decade now....