On the original dab you should have recieved a dab areial already fiked on the car. when the cars come of the transporter they have two aerials one in a bag with the centre caps and the handbook pack and the dab aerial lose in the boot if the wrong one was fitted at pdi that would explain a few things and yes they do look different if it looks like a standard ariel about 12 inches long and a continuos spiral down to the base then that is a standard fm one. basically compare it to any other seat if it is the same it is wrong
AS ABOVE