I recall when I bought my first hybrid that the dealer said there were something like 15 different computers controlling things, from the ICE engine to the transmission to the charging of the battery, etc. They weren’t networked together.
I also once ran afoul of a software bug in the ECU of a Honda CR/V. That’s the embedded system that manages the whole operation of the engine - from fuel injection to timing to emissions etc. As they progress through model years they use different ECUs that require different software. Even though I work in IT, I wouldn’t feel comfortable trying to update it myself, given the different models, firmware revisions, etc. I was more than happy to take that car to a dealer to have them confirm my car had buggy software and to upgrade it to the right new version.
I doubt it would help. My employer uses Akamai as a CDN & security provider for our websites. Their bot analysis tools regularly flag distributed bot activity that can come from a handful or a few thousand IPs. They do a range of browser fingerprinting, TLS fingerprinting, etc. to uniquely identify traffic across ranges of IP’s. I’m sure Google/Youtube has the ability to do this as well.
Any given client would need to regularly randomize the order of headers in requests, randomly include/exclude optional headers, and also randomize TLS negotiation to try to circumvent all the fingerprinting these big corporations perform.