Avoid doing them in the first place? It's not like bit rot is - or should be - a problem for cars. It's a problem specific to the Internet-connected software ecosystem, which a car shouldn't be a part of.
So basically: develop software, test the shit out of it, then release. If you happen to find some critical problem later on that is fixable with software, by all means fix it, again test the shit out of it, and only then update.
If OTA updates on cars are frequent, it means someone preferred to get to market quickly instead of building the product right. Which, again, is fine for bullshit social apps, but not fine for life-critical systems.