COE prices finished mostly higher despite the long Chinese New Year break, with bidders competing for a smaller supply of certificates.
The only exception was COE prices for cars up to 1600cc and 130bhp, which ended slightly lower at $25,689, down from $26,170.
COE premiums for cars above 1600cc or 130bhp closed higher at $34,509, up from $33,989.
The premiums for Open COE, which can be used for any vehicle type except motorcycles but which ends up mostly for bigger cars, closed higher at $35,310, up from $33,689.
Commercial vehicle COE premiums crept up to $26,378, from $26,230. Motorcycle premiums ended at $3709, up from $2889.
The supply of COEs for the February-April period is around 10 percent smaller than the previous three-month period.
Motor traders say this might have spooked the market.
COE premiums usually dip after Chinese New Year because showrooms are closed, and buyers are away on holiday.