For me it is a peace of mine thing. I have used Damien Trombetta at Allied Solutions Insurance Services, LLC. He sells Mercury policies.
My BMW SA recommended Mercury as being the best company for extended warranties.
His phone number is 800-826-9384 x 23319, his email is
Damien.Trombetta@alliedsolutions.net.
My family and I have bought 5 policies from him. Besides being a happy customer I have no other affiliation.