From what I read, and I could totally have Misread it, but I think it said that for 2019 MY the JCW came with the UJ lights but the non-JCW did not, as mine does not. If I got the rear lights from a 2019 JCW or bought them from dealership the only thing would be the coding, correct? The fitment and plugs should be the same? (reading the 2020 plugs are different).

I already did an overlay on the tail lights but it just isn’t good enough.

 

FYI, I have a 2019 F54 JCW, and it did not come with the UJ taillights. And yes, It has the LED headlights

 

UJ taillights didn't come until 2020.

 

I could have sworn I read that or saw it on YouTube. Phooey. Do the 2020 light fit in the 2019 then?

 

Physically they fit, but from what I've seen here you need a special wiring harness and possibly some coding to make them work. I'm no expert, though.

 

I see a lot of brits mistakenly calling their 2020s a "19" plate or 69 plate" or a 2019 year because they got it after march 2019, even though its a 2020MY (model year)

They started production in 03/2019 as 2020MY cars. Union Jacks did not exist prior to the LCI (refresh) clubman