I think you need to tell Kia that then, they would not take into consideration the painting of the bumpers, thus the buy back route... I'll get out while I can instead of having to fight with them to get the rest of the car painted "under warranty".. if they would do it under warranty, it would make more sense to do it at the same time you are doing the rest of the car, no?
Yes. But does this make sense? Kia says, repaint the car, and decided within thirty days if it meets your satisfaction. How in hell is a car returned to you with pristine metal paint and still chipping/flaking bumpers going to meet your satisfaction? If Kia is trying to get these cars to stay put and not get rejected, then they have to allow the entire car to be repainted. There is some kind of communication fubar going on with more emotional, less rational, owners of Yellows (and the other colors are standing by saying "why is my problem less important/valid than Yellows?"). Kia cannot possibly be saying: "Repaint the metal, ignore the rest and tell us that you love your car and will keep it." They say they'll send a cheque for five thousand grand! Is that supposed to induce YOU to let the rest of the car slide? I don't think so! It's supposed be their, "we're terribly sorry that you/we had to go through all this. Please accept our apologies!" But nobody is going to take back their car if the bumpers don't get painted pristine at the same time as the metal parts. NOBODY. Because the car will look like a bad hellish joke.
So just make sure that "your" body shop, or dealership (if you never see the body shop yourself), knows what-all is going to get painted: and it's the whole danged car. Then sit back and wait. When the car is done and you look it over, it will be gorgeous. You will want to say "yes, I'll keep her", because she will be so knocked down dead gorgeous.
The upshot? Kia pays for the whole thing if you say "yes, I'll keep her". In a very few cases, where there is some question about road damaged bumper paint, maybe, MAYBE Kia will argue with the added on cost. You can argue back. You now have your car and your $5K cheque is in the mail. But I'm guessing, from what's been said over and over on this thread alone, that nearly all the bumper chipping/flaking has already been verified and accepted by photo proof, through the dealer, that this is not road damage. And even though Kia has not included bumpers as part of the compensation deal, they have to honor the 36 month paint warranty on the rest of the car.