It looks like an after market DAB aerial. I had a AUTODAB interface fitted a week or so ago at Halfords. At first the signal was very poor but now it seems to have settled down and I am very happy with it. Cost of unit and fitting was £200. If you do have the same as me this is operated by holding the Telephone button down then a voice comes on to say "Autodab On". It is tuned to oneof the FM Freq buttons (87.8mhz).
Not straight forward to operate but once sussed all ok.