First post, please go easy.
I believe both offers can be stacked, and used as a discount off the price of the car. A few models are excluded, check the fine print for all the details.
Usually these specials mean the dealer won't knock much off their drive away price, but you can always try.
You can usually get $1500 off the drive away sticker price by negotiating, but might be a significant benefit if this promotion is being paid for by the manufacturer rather than the dealer.