Confronted with the general dilemmas besieged by limited land resource and traffic congestion, land transport authority of Singapore has successfully implemented the Vehicle Quota System (VQS) to control the vehicle population. The VQS requires each new vehicle buyer to bid for a license, called Certificate of Entitle (COE), for the registration of her/his new vehicles. This study will examine the quantifiable and unquantifiable determinants of the COE premium for cars in Singapore firstly, based on a revealed reference (RP) survey and some related literature reviews. Through the collected real data, the impacts of these determinants are further analyzed by formulating an autoregressive model with exogenous variables, which is verified to well fit the trend of the COE premium. Thus, the autoregressive model can be used by the authority or bidders to understand the feasibility of VQS and to estimate COE premium changing trend more reasonably.