This paper explores using the first subsymbol in the structure of a GFDM symbol as a pseudo circular preamble. As data and training sequence overlap in the GFDM structure, an initial estimation approach for isolating the preamble information from the data is presented. The concept allows for adaptation of state-of-the-art techniques developed for OFDM in order to estimate time offset at every GFDM symbol. The paper studies the proposal in the context of vehicular communication scenarios and assesses the performance of single-shot estimation of time offset. Both, line-of-sight and non-line-of-sight scenarios with doubly-dispersive wireless channels are considered and compared with the CP-based method from the IEEE 802.11p standard.