Too good to be true?

I’m trying to figure out whether this is too good to be true: My father got a pitch from, owned by ACS, which promises to lower his car least by almost half. I can’t find the trick. The means either that the GMAC lease he has is so stuffed with margin that it’s easy for another company to come along and do this… or that there’s a trick or hidden fee here I can’t find. Any wiser minds than mine able to figure this out? Is this a case for Consumerist?

: LATER: My father talked to someone there. Turns out you need to add lease buy-out plus the residual value and that raised his payment. Oh, well. No free leases.