principal engineer would be around that 20-25k per mth.
bonus depends on coy performance usually 6-8mths.
car allowance is about 3-6k depends on how you nego.
housing allowance is another 6-12k depending on how many dependants you have.

HR will always try to short change you.

remember to ask for
- spousal allowance ( 80% of wife last drawn pay)
- kid's education allowance.
- scholarship for MBA
- quarterly Business class return airfare.


remember to keep in mind that life in singapore is very expensive.
a typical equivalent suburban property compared to where you are from is about 3-5million. monthly rental is abt 10k.
for apartment its about 4-8k depending on size and location.
decent car is about 150-200k. even for rental of car its about 5-6k per mth.

congrats and welcome to singapore!