I think you're out of options. Mitsubishi's official promise seems pretty empty. Actually, looking into this reminded me of another example of Mitsubishi's apparent lack of integrity. Look up Mitsubishi on Wikipedia and you'll find this,
"In what was referred to as "one of the largest corporate scandals in Japanese history",[12][13] Mitsubishi was twice forced to admit to systematically covering up defect problems in its vehicles. Four defects were first publicized in 2000, but in 2004 it confessed to 26 more going back as far as 1977, including failing brakes, fuel leaks and malfunctioning clutches. The effect on the company was catastrophic, forcing it to recall 163,707 cars (156,433 in Japan and 7,274 overseas) for free repair.[14] Further recalls by Fuso truck & bus brought the total number of vehicles requiring repair to almost one million. The affair led to the resignation and subsequent arrest of president Kawasoe, along with 23 other employees who were also implicated.[15] Three of them have since been acquitted, with the judge stating that there was no official request from the Transport Ministry ordering them to submit a defect report.[16]"
I don't hink I'll ever buy a Mitsubishi product. It seems that you can't trust them when buying a TV or a vehicle. Fortunately, the USAAF and USN took care of most Mitsubishi aircraft. Now THAT'S salty.