I would be very careful when buying none factory extended warranties--most are rip offs.
The best advice one could give, is to go to any Jaguar dealer, or major auto dealer then go to the cashiers office and ask questions about these warranties--by name-- and see what they have to say about their policies and receiving payment and what they allow-----new, used, after market parts etc. Some will allow any kind of replacement parts. Also, you better make sure that as the age of the car goes up, does the original coverage still apply.
I took one of the warranty solicitations to my Cadillac dealer once and they told me to run, not walk away fast. Be very careful.