I got the same message! Mine was cut off & I only got the tail end...telling me that if I didn't respond my coverage would be cancelled.

Missed Cell phone call --  Caller unknown --  How do I block calles like this??

since i do not answer numbers that come up on my caller id that i do not know, i ignored this number. they left a partial message that my car warranty was about to expire, interesting since i have a vehicle that has an extended factory warranty. looks like a new number of many that are hawking car warranties. i reported it to the fcc.