[legion]

Yes, they are ripping you off.

I get the same offer from National City in a mailing every month. They even charge a monthly "convienence fee" of $50. (Which in my case all but wipes out the extra equity of those two payments.)

Truth is, you'd be better off just dividing those two extra payments by 12 and adding that amount to each month's payment. Make sure you specify that the extra is to go to principle or they will put the extra in a "holding account" for the full year!

It's really a scam for people who don't understand math and can't budget well. In your case, it has no harm and no real advantage. Might make sense for people that can't figure out how to save out of one paycheck and would otherwise always be late. In my case, it's a blatant ripoff.