This is a classic example of price discrimination. Slowly but surely, companies such as Toyota will converge to a state where every consumer individually pays the maximum amount that the consumer is willing to pay for the product.

$8 a month may not seem like much compared to the cost of a car, but that's the point. Toyota will be able to get free extra money from a large population of people (many of whom will later barely even remember that they are incurring this regular cost).