I updated my 2017 CT with a USB from satnavishop in 2022. Just followed their instructions, "Started" the car, switched A/C, lights etc. off and started the update. Took 100 minutes, and I'm not sure if the engine actually ran during that time, but had no trouble. It was a 2022 update but the map was dated 06/2021, so was already out of date. Haven't updated it since. If I'm going anywhere that involves new(ish) road layouts, I just use Google Maps on my smartphone in a vent mounted holder. Irritating when you've alread got a built-in satnav, but Google, and doubtless other phone based systems, are far superior to anything the Lexus system can offer. Shame it doesn't have a working screen mirroring system in the car.