I don't know anything about the dealer, on the other hand if there were complaints I would have found them,,, dealer appears to be legitimate selling GM warranties with low markup cashing in on volume.

I am not going to sway you one way or the other buying an extended warranty,,, but consider this,,, 16 to $1,700 plus tax and a service fee if something happens is a fair chunk of coin, something really nasty has to happen to go beyond your layout.