Some people, like my husband and I, are not deadbeats. We transferred our auto loan to the AMEX Blue Card because the interest rate for balance transfers was 2.9% until the balance was paid. We pay the same amount each month that our car payment was, which is greater than the minimum, and they screwed us last month by slashing our credit limit by thousands of dollars. This will hurt our credit score at the very same time we are applying for a mortgage. AMEX can bite me.
Your case is similar to mine. I took advantage of a balance transfer offer at 3.99% for the life of the loan, never got around to actually using my Blue card for daily purchases(which would have accumulated tons of interest charges while I was paying down the promo balance).