The high antenna is for Hybrids. Non-hybrids have the antenna built into the back glass on the lowe 1/3 of the glass. Because of the NiMh batteries behind the back seat of the Accord Hybrids, the vent behind the back seat intereferes with the signal, therefore, the hybrids have the regular antenna. The flat portion on the roof that is seen on most Accords is for XM though.