Security is a major concern with connected cars. If the public don't trust connected vehicles, people won't buy them. So, the blockchain could be a good solution to offer a strong security and gain trust from buyers.
However, I'm wondering if the industry and the insurance companies will encourage the development of digital maintenance logs and connected cars. If they think these technologies could reduce fraud and lesser the number of accidents, they will probably encourage people to buy connected cars.
There is another interest for insurance companies to push the market to adopt connected cars: collecting data. The personal data could be used to adapt their contracts: if you drive safe, you pay less. If you drive safely, you would pay less on your insurance. If you drive with a dangerous behavior and if you were involved in several accidents, you would pay more. But the various data collected by a connected car could also be sold to third-party companies by the insurances.
Buyers and governments should care about this problematic to avoid abuses with drivers data.