Sounds like a fair deal to me, but I would ask them to make special note on their system that even if your motor had to die after your extended warranty ends, that they honour the fact and acknowledge that the engine problem as as a result of their faulty airbag in the first 2 years, and not through any fault of your own.
Not saying anything will happen, but should it later down the line, at least Brian's acknowledgement is on record for your sake should another customer service representative eventually take over from him during this time.
Well done.