Looking to buy an '06 diesel megacab. I've encountered some manufacturers' buybacks in my search. Would I be an idiot to even consider these? One in particular was returned for an unspecified check engine light and the "repair" was "could not duplicate". I'm a commercial pilot and chronic write-ups followed by "could not duplicate" are a huge red flag, so this one is a no-go. But it got me wondering about the buy backs in general. Under what conditions would it make sense to pick one up?