Its your car - the color of the interior really won't affect the value of the VX. This isn't a numbers matching kind of deal. I'd say go with what makes you happy, so if thats the black interior (which I have) then go for it. I personally think that the red interior gives it some.... pzzzaz? Is that enough z's? The black interior can get a little tiring.

Just make sure the Ironman checks out mechanically, thats most important. How do you have a full black interior lying around anyways?