The issues seems to be with an old model, people talk about 2007, 2010 models etc. If they have USB ports, they'll probably be charge only, or only connected to the audio system / infotainment for iPod playback (latter might be an update path if its an infotainment system only issue). You can probably only do control unit updates over CAN (or custom methods), so unless you're a particular type of car enthusiast only a garage will have the tools.

Plus the general digital archaeology needed to get a decade old project / branch and get it and the developer tools back into a state where you can compile and test it. Probably hard to get a fix in a few days if its only just been found. That's if a non-safety critical issue on a 10+ year old car that will fix itself in 8 months is considered worthy of fixing.

In more general I suspect car companies are a bit reluctant for self-service updates like that because of the potential to brick something. If the clock problem is just tied to an infotainment display, losing that would just annoy the customer until it got to a dealer. If it for example disabled the instrument cluster, then that's a safety issue and might make the car illegal to drive (depending on local laws). If its at a dealer, a failed update can be fixed directly by the technician (replace part, or use alternative programming method etc.).

Although newer cars (particularly Tesla) are perhaps seem a bit more happy to do things like OTA updates. You really hope they don't take a "build fast and break things" approach to development. And have good self-recovery systems.

These infotainment modules do have DVD updates available, although it's unclear what code the DVDs can update (they can certainly provide a new version of the mapping application so it's evident they can replace code as well as data, but I don't know the system enough to know if they could update other functionalities). It's also unclear if the issue is too systemic to be solved by updating a single module. But, generally speaking, infotainment is already much more user-update friendly than you suggest - many infotainment modules will take (hopefully signed) updates over DVD, SD, or USB.

The good news: you can fix your car's firmware by plugging in a random USB fob.

The bad news: you can fix your car's firmware by plugging in a random USB fob.

This is actually pretty common and for the most part the updates are signed and require user action to install. Now, of course, the signature checking is usually broken, because it's automotive stuff, but it is there :)

Or do what HP does, charge $35 for a Floppy disk instead of offering it for free download because you know, someone could use this device driver made for a specific HP model with some other hardware... /s

Floppy disk? You were lucky. When I contacted HP they sent me a box of punch-cards... /s