just moved to hk from tokyo recently, and bought a porsche 987 boxster s.. not too bad a px, got a 10% discount from dealer. i know a lot of people like to wait for good deals (and probably not picky about what they get) but though those are classic/collectables etc, the suspensions and comfort level in those kinds of cars must be pretty bad on the roads in HK... before i got this car, i rented a 10 year old merc slk and drove Okinawa (islands off Japan) and it was horrendous, everything felt like it was about to fall off, the seats felt like alligator belt, and the pickup was arthritic..
If you really love driving, it must be torture to wait for a better px before getting out there driving... i cannot wait...
Also i agree the registration tax is crazy, but though i moved from japan which has the cheapest used import sports car market in the world, singapore has even more expensive cars!! due to 100% tax for all cars (not just high end) plus something called COE (Certificate of entitlement) which is about GBP 10k for just a piece of paper...