With the help of Joshua A I installed a Boom GTS radio out of 2020 into my 2018 CVO. The radio I purchased has a part number that ends in an A. That is what the new Boom kit is showing as a retro fit radio. Out of the 2020 the radio would not work in my 2018. The radio needed to be updated to the latest 2020 Harley Davidson update. I couldn't do this from my 2018. My buddy allowed me to plug the radio into his 2019 and update it (I updated his also while I was there). After the update the radio came to life when installed in my 2018. Going from the GT to the GTS is a big difference. The GTS is so much faster. Now if only they would add Android Auto!
The radio I purchased with the A part number.