Full-duplex (FD) technologies promise to improve the performance of vehicular communications by enhancing the IEEE 802.11 medium access control (MAC) standard with collision detection capability and the simultaneous transmission and reception of data signals. In this paper, we propose a FD-based MAC extension for multi-channel vehicular networks based on IEEE 802.11. The solution is tailored to support platooning, considered as a crucial use case on the roadmap towards fully autonomous driving. A Control Channel (CCH) is used for the platooning service advertisement, and a Service Channel (SCH) carries data among platoon members. The on-board units in vehicles use FD capabilities to access both types of channels. Early achieved results show that the FD-enhanced solution is able to provide (i) higher reliability for the broadcast advertisement procedure carried out on the CCH, through a FD-enabled collision-detection mechanism, and (ii) increased capacity on the SCH, through FD-based simultaneous transmission and reception of messages among platoon vehicles intended to feed the driving control algorithm. These early encouraging results solicit further investigations to demonstrate the FD potentials in vehicular networks.