I'm posting this since neither the Varia Radar, nor the Varia Vision appear to have a sticky for firmware updates. Feel free to edit/remove/sticky or whatever.
-------------------------------------------------------
Varia RTL510, System software version 3.70
as of December 18, 2019
Use Garmin Express to install this file.
(475 KB)
Notes:
WARNING: If this software is uploaded to a device other than that for which it is designed, you will not be able to operate that device.
If attempts to upload software fail, you may need to return the device to Garmin® for service.
Change History
Changes made from version 3.50 to 3.70:
Improve radar handling of very high-traffic environments.
Improve radar target speed reporting.
Changes made from version 3.40 to 3.50:
Fix issue with firmware version reporting that affected some units.
Changes made from version 3.30 to 3.40:
Improve close, slow moving vehicle performance and false detects.
Changes made from version 3.20 to 3.30:
Minor improvements to radar performance.