From what I know, the 7 yrs is from the in service date. It basically adds 4 years to your original service contract.

There is no advantage (unless it is in rental cars, or 'perks') that I know of for purchasing it from the get-go, aside from the fact that some people want to roll it into their financed price.

You can buy the extended service contract up to 4 yrs/48k from original purchase/in service.

SQ