Looking at kia.ca and mazda.ca I think the pricing between the 2012 Optima Turbo and 2012 Mazda3 GT-E Auto is closer to $5200. The purchase price of an Optima EX Turbo is $32,469.42 (Includes Alberta taxes, freight and rebates). A Mazda3 Sedan GT-E Automatic is $27,199.31 (Includes Alberta taxes, freight and rebates). The difference for financing is $34,729.42 and $27,199.31 respectively, over $7,500.00.
The Optima is still one heck of a deal IMO.