Yup exactly. I've just spotted
this - this should be big enough to put the camera inside, though will look a bit silly on the car, but hey, who cares? I'm happy to remove the existing aerial completely - the rubber base has perished anyway, and is probably going to start leaking water in the car. Will need to figure out what exactly to use to stick it on the roof, I don't think silicone sealant is strong enough to hold that on at, say, 80mph.