Just had mine installed a week ago, which was about a month after I requested it. My dealer also told me they were more readily available now which is why mine came in much sooner than originally expected.
Known situation; has been that way since the JL came out in 2018, and maybe even with earlier models. Just a bad design, but not something that can be “fixed” without some aftermarket engineering. I’ve seen a few versions of different “channel extensions” that people have applied, but none...
When you get the cap in, make sure the part number matches what the listing on Amazon says.
Here’s that same part number on another site that sells Mopar parts and you can see it shows it fits all JLs:
https://www.allmoparparts.com/sku/82215184.html
Bought mine here, and yes 2018-2021 will be the same.
Mopar 82215184 Jeep Wrangler Locking Gas Cap https://www.amazon.com/dp/B07BQG4JHZ/ref=cm_sw_r_cp_api_fabc_2OeXFbBNBG2KR?_encoding=UTF8&psc=1
This is the OEM Mopar one that can be keyed to use your Jeep key so you don’t have to carry around...
Sorry, Rubicon here so my part numbers wouldn’t help you. I could look them up on Rancho’s site, but would prefer to hear from someone that actually has the Sport versions to make sure you get the right thing.
I have the Rancho’s too and they allow the access needed to change the diff oil. Are yours an older design or something?
FWIW, I also have the Rancho shock skids, and a MORE oil pan / tran skid.
If it was anything other than the gas pedal, I’d agree with the heat suggestion. But the gas pedal just snaps on. I had no issues with mine. Maybe it needs to be heated too though in some cases.
I used a hair dryer on my brake and clutch pedals btw, seemed to be easier and faster than the hot...