Go to leasecompare.com and see if you can lease from them. Much better rates than Mazda and you don't have to deal with car dealers trying to sneak in fees and higher rates. I don't see any reason why a dealer wouldn't lease an MS3. They're not getting any less money for it than if you bought it cash. The leasing company buys the car from the dealer at whatever price you agreed to buy it at and then you make payments to the leasing company. At the end, you give it back or you can buy it out. If you give it back, the leasing company owns the car and do whatever they do with used vehicles.
EDIT: Looks like $595 a month, no money down, for a GT at $23,500, 24 month lease, 12k a year with a money factor of .00415. You're going to get screwed on a 2 year lease because that's where most of your depreciation is. I'd go with a 3 year lease. The payment will go down to $401 a month with no money down.