no solutions through mazda at this time. There are multiple bluetooth kits available aftermarket, but they tend to be pretty pricey. I would love to have integrated BT though.
Funny story. My friend's BMW has BT built in. He switched services, so he gave me his old phone (black razr). We're driving somewhere one day and he's about 40 feet behind me. Suddenly my phone goes dead, and on his end he just keeps hearing his own voice coming out of the speakers when he talks into his phone.
Turns out that my phone connected to his BT system from my car. It took a minute to figure out. (crazy)