I was a little surprised too because I have done a lot of research regarding the MFD2 > RNS 510 upgrade and nothing warned me of this. Basically, the back wall behind the player is straight and without any places to thread through the aerial lead. The head unit is fitted at an angle, slightly tilted so that the top of the player is closer to the backwall than the bottom. The aerial inputs on the bottom (FM/GPS) will therefore have plenty of clearence to the back wall while the DAB connector on top does not. I will take a picture the next time I open it up.