Highest firmware revision depends on which model of RNS-510 you have. See:
https://www.ebay.com/itm/2015-5382-...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649
There he gives firmware versions VS RNS-510 versions. I chose to buy my firmware (for USA “J” model with version 4369, indicating I have an SSD, apparently not all J versions do) update from him. I’m sure there are less expensive options to get the firmware. However Peter was a Continental dealer and repair service until 2015, when development of the RNS-510 stopped (so I read). I decided that his knowledge was worth the cost to me. He noted that there were “tons of bug fixes from very first SSD based firmware 4369. 5238 is some seven versions news than 4369”. He also answered that the firmware 5238 will not “reformat” the SSD, thus losing all my maps (I have the map DVD also). I then asked about Bluetooth and MDI firmware updates, which he stated “there were no updates, even from VW”. I don’t know where else I could have gotten such advice.–george
I did the firmware (& operating system) upgrade in about an hour, as Peter states. Some of the prompts from VW area bit scary, but as Peter says "just wait it out". Prior to firmware upgrade, the startup screen (VW logo in foreground, map of the world in background) was shifted with a horizontal split near the bottom of the circle surround the "VW" letters. This was not a problem, merely annoying. The firmware upgrade fixed that too. I guess the picture file was reloaded as a part of the upgrade. So if you have the "split VW logo" try reinstalling the firmware. I don't know that I can tell that the RNS is any faster, or GPS performance any better, but I sure feel better with the latest. Peter notes that Sirius XM reception will be improved, but I'm too cheap to subscribe.
I've been corresponding with Peter and asked for a (semi) technical description of the operation of the RNS-510, and he responded with:
In regards to technical aspect of the OS running on RNS-510 it is of similar to unix. I'm no expert in it, as I only have factory tools from Continental to repair these units with their own interface. For example when replacing a hard drive the NAND memory partition has to be wiped before full firmware can be installed to initialize the hard disk drive and partition it properly.
In regards to boot and what happens during boot is fairly simple. Each function is launched almost like an app and runs in the background. To what I know Radio starts first, then rear view camera, sirius, and last is Navi portion of the unit.
These are not the quickest units out there but the last revision of them with SSD drive is very solid unit and easily repairable if something should go bad as there are parts available for them.
Newer units I sell from MK7 cars called MIB2 are much more complicated as they tie into the cars electronics so deep, that if not coded correctly systems of the specific car module can shut down. We are reaching a point in time, where car radios will no longer be replaced by third party, and car manufacturers want to eliminate third party parts installation on any cars as it causes a headache for them, and people want to claim warranty caused by these parts on many occasions.