If I had to guess, I imagine auto manufacturers allocate some amount of the sales price towards future recalls as well. A little googling seems to indicate I'm at least partially correct:
A major recall that affects a large number of cars can create huge expenses in the aggregate. According to Toyota's Q3 conference call, they have set aside 100 billion yen (approximately $1.12 billion) for these "quality-related expenses" which will be allocated between the third and fourth quarters. (Some products were announced with great hype, only to be pulled from shelves. Find out more in A Year In Product Recalls.)[1]
I suspect that legally required recalls are viewed differently than security updated mainly because they are legally required. I wouldn't mind a consumer law requiring companies to provide at least a minimum period of security updates from the time it's officially available from the manufacturer. I also wouldn't mind if that period was longer for "appliance-like" IoT devices...
It probablt can even use the same justification. Unsafe vehicles on the road are a danger to us all, and so are unsafe devices on our networks.
1: http://www.investopedia.com/financial-edge/0210/the-cost-of-...