Here is what I got from ebay for my NC. It fits well and you don't have to dismount prior to covering the car.

Mazda Miata MX5 Foldable Antenna | eBay

 

Excellent! I love solutions for problems nobody has. I hope you make a fortune selling them.

 

Actually I have been looking for something like this. I have a custom fit cover for my 02' and I haven't replaced the super long power antenna yet because an always up won't work with my cover. That is a decent price too.

 

I might be missing something, but I can only see someone replacing a convenient, retractable power antenna with an always up version for looks, like sleek, fixed, shark fin-style antenna. I feel like this is the least attractive of the three options which would sorta defeat the original intent.

 

Redcap, not all Miatas have retractable antennas. This one replaces the fixed long antennas that you need unscrew before covering the car. Neither is this one a shark style.