If those cars had been been mandated by law to be exactly the same and perform exactly the same, then your car analogy would have a point. Since they were not mandated to be the same, it doesn't even come close to comparing on a med sup.
Your absolutely correct! I too spent over 15 years in the car business. While I agree with the other poster in "sell yourself..." which is an old car/sales mantra, cars are somewhat unique, especially used cars. In used, there are no 2 alike, at a minimum condition and miles will be different if all the rest is equal. That is NOT the case with Med Supp at all!