Mounting / hiding a mast style antenna

[bd8134]

I want to put an electric mast retractable antenna in my car but I do not want to have the regular bezel and mounting nut visible / above the fender. I was thinking about making a bracket which the bezel and mounting nut fixes to so just the top tip of the antenna mast protrudes through a hole in the fender so that it sits flush.
When the radio comes on the mast will extend through the hole in the fender.
I am thinking the tip of the mast might need to be larger then the stem of the mast so I might have to make a larger hole than just the tip. Also I will not be able to lean the antenna backwards as it will require a bigger or oblong hole.
Has anyone some ideas how to do this or used an antenna they liked for this purpose. I do not want to do a sunken hole for the antenna.
I also do not want to use a window, foil, stick on type antenna nor a shark fin.
I enjoy listening to the radio and specifically HD radio.