First off, this is considered a FIRMWARE update. It updates the HARDWARE for the dashboard using a software download. Technically a software update is something different. That might sound nit-picky, but I spent 26 years in the Air Force doing Network Operations, so I'm a Nit-Picky Computer Geek. :roflblack:
Whatever version of the update is installed on your Spyder should be listed (shown) on the dashboard display if you use the dashboard menu selections to get to where it is displayed. You will want to go to Settings/About/? (the question mark) and it will list BOTH the Software and Hardware (Firmware) versions installed. IT SHOULD BE V020.80 for the Software Version (see pics of my dashboard below).
If your dealer tells you the update is not for the 2018/2019 Spyder RT, tell them it IS and to plug in the cable. Their in-house COMPUTERS (sitting on their desks) database may not show your 2018 or 2019 RT has the update available. That is an error in their dealer's desktop computer database tracking system (and isn't their fault). If they plug in the cable to your 2018/2019 RT it SHOULD tell them the update is available and they SHOULD be able to download and install it. How they get from whatever version that is on your RT now to the newest version 020.80 is up to them. If they say "no" and insist the V020.80 update is not for your 2018 or 2019 RT, you need to go find another dealer that knows about their own products they sell.
Where to go in the Menu selection (click RIGHT one more time for the ? in the "About" section)
After selecting the ?, the 2nd line down under "Version" should show BOTH the GSS SW and CSS SW as V020.80. THAT IS YOUR VERIFICATION. Yes...yes...the "SW" stands for "software", and the V020.80 is the name of the "software version". The line underneath that shows the Hardware Version (the HW). In this case, the software update is updating the hardware (Firmware) too...but that does not always mean the hardware version number will change. That's the "nit-picky" part of what I was saying at the top of the post. The Air Force spent a lot of money teaching me stuff like that.

hyea: :thumbup:
If your dealer is awaiting a new cable that works, they might NOT be able to even tell that the update is available for your Spyder RT. As of about a week ago, my dealer's BRP database system did not list the update as being for the RT's...only the F3's. That is just an error in their databases. Plugging in the cable to your RT SHOULD show them the update is available if it hasn't already been done.
Hope that all helps answer your questions.