You make a good point but, the best APR I could find was 5.99%. I see what you mean and agree but I went around it in a different way. I paid down $10,000 and financed the remainder. So gap protection was not really needed all that much but it was $600 bucks so I got it.
Here is the math with 5.9% and 4000 rebate = $38,471.06
With 0% and no rebate = $37,999.86
And that is total gap, extended warranty and TTL. So 0% made about $471.20 difference, not much but I will take it. And if I decide to trade or sell it I hope the $10,000 I paid down will give me some room to work with.