I suspect that personality traits are going to be far more important in determining purchases than IQ but some sort of explanation of what the types people are referring to would be helpful. What the heck is a INTJ? Are those people predisposed to becoming mass murderers or are they the type who wear jackets with leather patches on the elbows and visit car dealerships with clipboards and questionnaires?
BTW: I have actually come across several people with clip boards and questionnaires on car yards. One gentleman I distinctly remember came in, filled in his form then came back a week later with a supplementary questionnaire and told me my car was "in contention" to which I replied that it was a very good well priced car and would sell quickly. When he returned another week or so later to tell me that my car was the one he had selected to purchase subject to a test drive I informed him that it was sold and delivered to somebody else.