Hi Yongxi,
Just get it checked by a BM specialist, any car either from Japan or Singapore can have it's share of problems. True about the heaters being blocked out, only the older models though, probably pre-95's. Later ones are ok. The "Singapore car issue" was actually a rumour that started about 9-10 years ago, I'm guessing by Dealers importing from Japan. The cars from Spore came in with higher Specs and were well priced. There was tension among Japan import dealers with European cars coming from Spore that were priced significantly lower than Japan imports. Lots of rumours about humidity,heat and all that stuff..(FYI no humidifiers in Spore) More likely condensation will effect electronis parts, with change of weather and temperature. In Singapore its Summer all year round.. So, like I said it was just a rumour that started and actually caught on well with the general public, so having a Spore import now will be harder to dispose off, unless it's cheaper. Hope that helped. Cheers