Hi,

One, Not many Singaporeans can afford cars these days. They are in debt. They don't think about the 90k COE. They think about the 1k-2k installments every month. They look like they are rich but they are the poorest people. One retrenchment and recession is enough to drive them off rooftops.
Two, COE prices is driven by rich who buy second or third cars 'for their children. Considering many singaporeans born in sixties are in good financial shape due to growth of singapore in the last forty years, their children are now between age 20 - 30. The cars are for them. But it has taken a toll on their savings.
Three, cooling measures have little effects as there are many back end deals done by developers to 'rebate' these costs.

To answer your question, yes singapore economy is not 'doing well', we look like we are, but we are very vulnerable economically.