This paper proposes a multi-functional vehicle -to-grid(M-V2G) interface based on the new fundamental active current(FAC) extraction method for shunt compensation(SC) with enhanced dynamic response. The M-V2G operates in four modes, namely(A) active power injection(API),(B) API and SC,(C) API and partial SC, and(D) SC. The proposed FAC extraction method involves processing the d-axis current of non-linear load through the cascaded band-stop filter. The resulting signal comprises a dc and an ac component with six times the fundamental frequency. For balanced currents, FAC is derived as the value of this signal sampled at the absolute peak value of its derivative. For unbalanced load currents, FAC extraction considers(i) the average of six consecutive samples, or(ii) inclusion of an additional BSF with a center frequency corresponding to the 6th harmonic is included. The second option provides a faster dynamic response. M-V2G interface is controlled based on the FAC and commanded API. The proposed technique ensures accurate FAC estimation without complex computations, as evident from the pseudo-code and experimental studies. Further, the experimental results confirm its effectiveness, feasibility, and practical viability. The M-V2G interface with the proposed FAC estimation scheme increases power quality and VA utilization of the V2G interface.