I had a gift card to spend at 1 of my local HD dealers.
It has always bothered me that the Freewheeler gas cap did not lock. So after wandering around for awhile, gawking at thinks I could buy, and there are a lot, I decided to spend some of my gift card on the
HD Bar & Shield Self-Locking Gas Cap (Chrome). I know it's somewhat anal, but I will sleep better at night.
For the left side I am considering 1 of the aftermarket caps that has LED's for the fuel level & voltage, to replace the OEM fuel gauge cap.
HD does not sell those, theirs only has fuel level indicators.
I really like the sets that have the flush mount caps, but still no lock.
Another cool to me item, is the Battery Tender digital volt meter that plugs in to the SAE charging connection.
It's very compact & I have read reviews saying it's also accurate. I may pick 1 of those up while getting the cap I ordered.
Here is a link to the gas cap:
https://www.harley-davidson.com/store/bar---shield-self-locking-fuel-cap-pa-04-61100129--1
Here's a link to the Battery Tender digital volt meter:
https://www.revzilla.com/motorcycle/battery-tender-digital-voltage-meter