if you don't want to spend 350 dollars on the cossie go with one that keeps the stock MAF tubing, the sensor needs to have a venturi effect for it to function properly, k&n and aem don't feautre this and create a cel on some cars.
go wtih the focussport, and you can install it yourself, all you need is 3sockets, 1/4" ratchet (3/8" helps too) and a phillips and standard screwdriver...