Prius "Fin" on top? How to install?

this is about what I paid for mine.
Install - Easy - unscrew existing antenna.
Attach Fin antenna cable - (screw into now empy hole)
Place fin in proper location.
My biggest challenge was lining up the fin properly.
I placed 'painters tape' to mark location/direction.
Made many changes until I had what I thought was perfect alignment.
attached antenna, removed double sided tape from bottom of fin, lined up on pre-marked locations and pressed firmly.
Works well, some say slightly less FM reception, but I have never noticed.

 

I do not think that anyone sells it cheaper than the PriusChat Store.

Regarding installation, it's peel 'n' stick. That said, alignment is an issue and the installation instructions are odd or wrong. I have two installation tips:

1. When centering the fin and marking the roof with masking tape, I strongly suggest that you use a tape measure to ensure that the location for the rear corners of the fin are marked to be exactly the same distance from the roof/hatch crack. Just line up and hook the tape measure end on that roof/hatch crack and measure to see that each rear corner is the same distance away.

2. The instructions say to peel and stick down the front tip of the fin down first. This makes NO sense to me. Instead, I would line up the rear corners on the masking tape that you've marked off, and then peel and stick down the rear corners first.

 

Before you stick it down permanently, connect it, and securely tape it with masking or duct tape, and take a drive, and see if you have any signal loss, AM or FM. I didn't, (some people have) but the preview drive made me feel better, before I stuck it down for good. I just "eyeballed" mine for alignment, and when I actually measured it it was off less than 1/16" side to side. Close enough for me. I love mine, and it works better than the OEM whip, and actually better than either of our Subarus with stock whip antennas. Go for it!