Given the facts you stated, the answer really is in your hands.
The W124 in Singapore vs a BMW E36 (or any car Jap for that matter) - no doubt, I'd go for the W124 anytime. Yes its a very durable car & DIY friendly. Plus the fact that an ancient car in Singapore is not "laspag" as it should be due to good & clean roads, clean fuels, clean environment & less stop & go traffic.
W124 parts are very much available in Singapore, so another plus.
On the 2-3 years left on the COE... hmmm...? do your Math & see if its worth the remaining years.
So + (plus) on the choice of car,

but - (minus) on the remaining COE.
