I just replaced the aerial for an amplified shark fin one, but it's no different to the standard one.
I have an Alpine DVD head unit which has a hideaway unit that I've got in the rear quarter panel (3dr). Previously the standard aerial ran all the way to the front and then was extended back to the hideaway unit. So when I fitted the shark fin this morning I ran it straight down the C pillar to the quarter panel. Also powered it up with the blue wire from the loom.
When testing in the workshop the reception was crystal clear for Radio 1, 2, classic and Lincs FM with a noticeable improvement when the aerial was amplified, but as soon as I started to drive again it all went fuzzy again
It is an old head unit now mind. Maybe getting on for 10 years old now...