I looked into the radio experience many years ago, did not take the plunge. However, as one who is "antenna aware" (long-time CB user), I have to ask: are you SURE you want a hard-mount antenna on the roof? Yes, it's much better for radio use, but it automatically means that you can not drive through a car wash. Depending on the length of the antenna, you might also have to be aware of parking garage clearances or even your own garage door clearance.
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