My car's built-in navigation can use dead reckoning based on steering angle and wheel speed, so is still better than TomTom in this respect. I really think this person who is clinging to their old TomTom is a bit oblivious to what all the alternatives now do and how they do it better.

Mhm - note that with "TomTom" I now mean Android app (which has Android Auto integration) and not an old standalone device :)

I've also seen that same very app as a builtin navigation with all the features (including live traffic) in a new Fiat 500e, so it seems like they're licensing the tech to car manufacturers.

I don't know if I'm oblivious - on long drives I usually have the TomTom setup and Waze on the android auto screen - TomTom knows about traffic and issues on the road that are just not on Waze, most of the time. Also Waze keeps directing me on most idiotic side little roads, recently I nearly got stuck in a muddy road somewhere in the British countryside because of Waze because I decided to trust it. Again, no such problem with TomTom.

waze acts as if it treats all roads as wide, level, straight paths, and expects ppl to speed on them bc it sends me on twisty, steep, narrow 25mph roads with low visibility so they canxt be sped on.

You can download maps offline in Google Maps

Despite having my area downloaded in Google Maps, the navigation and recommended routes won't load in my garage. It usually fails horribly (mostly because, like many poorly programmed mobile apps, it doesn't handle scenarios with poor connectivity well).

You can only download them in explicitly specified chunks (not e.g. one whole state, much less whole country), and they expire if you don't update them regularly.

Technically you can download a particular region as well. e.g. search for "Belgium", click on the ... > Download offline map.

However, it still downloads an arbitrary rectangle, and there is still the same maximum size; it just automatically centers it on what you selected and gives it a reasonable name.

I've had some pretty poor experiences with offline maps on Google Maps. There have been a few times where I've made a point to download the maps for an area a couple of days ahead of time because I knew service would be spotty. I would then drive out to the areas with spotty connectivity, and more often than not Google Maps would refuse to generate a route for a route definitely within the confines of the selected offline map. I'd have to drive back a bit by memory to find reception and then try to generate the route again. This would even happen if I was on a route, cancelled it for some reason, and then attempted to restart the exact same route while along the route it was just on.

Google Maps offline has been extremely unreliable for me and mostly unreliable when I had the greatest need for it. This was true years ago and this was true less than a month ago.

If I'm going to someplace with spotty connectivity, I make sure to put in all the main addresses and locations on my car's navigation system ahead of time. The maps might be dated but at least it'll generate a route somewhat towards the destination, even if I might need to take a detour along the way.

That is an edge case that Google could but does not seemingly accommodate, but very well could. It’s likely not just that you have no GPS, it’s also likely that you have no mobile or Wi-Fi signal reception, both of which could inform on your location, if implemented.

That being said, why do you need your navigation to start while in your garage? Just start it before you enter your garage or right as you drive out of it if you want to benefit from GMaps benefits.