I went to a dealer and they said it was impossible. I seriously don't know why you can't just put it on a thumb drive or make it available online. I mean seriously, it's 2019. Just download it via satellite.
I'm not sure why they said that, Upgrading the Prius Nav system is available through the dealer, I'm not sure why this would be any different. Whether it's worth it or not for several hundreds of dollars would be a separate question.
I went to a dealer to get my maps updated and do the airbag recall. I had the original 2011 maps and too many new roads were built in my area.
I was visiting chicago and found one dealer on the northside had the map upgrade usb in stock.
Ordering the usb upgrade takes 2 to 3 weeks if the dealer does not have it in stock and most dont.
FYI, I searched how to hack it to upgrade myself and could not find the US upgrade software to download. Your only option is through a dealer or buying the USB upgrade and spending like $1,500 to buying the toyota upgrade system which is not worth it just to do it yourself. It might be possible to clone the hard drive from another CT200h that already had the maps installed, but I could not find anyone that talked about doing that. Basically the 2011 to 2013 models get screwed with a ****ty nav setup that wont allow for DIY upgrades.
Cost to buy the map upgrade and install it was $238.48. The sales guy was going to do it himself. He said he could do it in 15 min. It could take longer as I read the upgrade software is finicky and it could take several attempts to get it to update. Also, I asked about the airbag recall so then it took 5 hours waiting for a tech to work on it. They gave a me a loaner car to use for the 5 hours.
Also after the map was updated, the nav until was glitchy and unresponsive. I first thought I got screwed with a bad install. I had to do a full reset to fix it and it has been fine ever since.
I have a 2012 CT as well and did the Nav update in 2017 at dealer. r81984 is correct, 2011 and 2012 CTs are f'ed up. They uses Gen 6 hardware and Nav update must be done via a Toyota NUT (Navigation Update System). I got an genuine Lexus map USB drive off eBay. Drive cost me around $70 then paid $99 to dealer to install. I chatted a bit with the tech and front desk people. They all hatted NUT because in order for NUT to go through, they first need to make sure entire car's firmware have to be up to date; otherwise, it will not go through. For older lexus w/ Gen-6 Nav, that means whole car update instead of just Nav so they charge higher fee for it. Needless to say, customers are not happy and they gets short end of the stick. So feedback went back to Lexus then they move on to Gen-7 and now Gen-9 that are much DIY update friendly.