question....should i extend my warranty for my 2001 M roadster?

ghead i live in CA and i try shop for an aftermarket warranty, but they don't offer, do you guys know why?
the quote i got from BMW dealer is: 6 more years / 100,0000 miles, for $3000. $0 deductible. do you think this is a good deal or you would advise otherwise?
thankS!!!