Aerial too long

I have a new Ecosport which I can get into the garage. However, on reversing out of the garage the aerial catches on the up and over door as the Ecosport sits higher than my previous Focus. What I need is a short aerial but Gates Ford say they dont supply one. They tried all the ford aerials they had in the showroom but none fit the Ecosport. Can anyone help source one as it would be rather expensive to have to replace the garage door just so I can garage the car!