Do I need an adaptor to connect the two FM antenna leads of the vehicle to the Z-E3150?

AW: No. The Z-E3150 comes with an adaptor interface, which fits to the double FM antenna plug from the vehicle. If this solution is not sufficient, e.g. the FM radio reception is deemed to be poor, the ZE-NC-ANT3 phantom power adaptor which is separately available, may help to improve FM signal level.