No dice.It's probably too late but if you log into "my tesla" on the tesla website it might give you an option to do so. A buyer might ask you to purchase it for them.
Just (re)read an email from Tesla from a while back: "You can purchase an Extended Service Agreement up to 30 days or 1,000 miles (whichever occurs first) after your New Vehicle Limited Warranty expires. Extended Service Agreements may also be transferred to subsequent owners."
Just missed it. I was debating getting it, but passed.