Replying to Taking AP Spanish test without taking AP class? Feedback please

so i have no room in my schedule at all becuase im trying to take hard classes and everything, but i have to have weightlifting for football, and i want to take one more class that isnt super hard. i need more spanish credits (ive only gone up to spanish 4, colleges want up to 6 now, which sucks). so i figured i might be able to take the AP test for spanish language class without taking the class. I would get the college credit too, which would be awesome. is it possible? could i get a 3 or 4 out of it? anyone who has taken AP spanish- what would i miss by not taking the class? I plan to use this computer program called the rosetta stone, and get all the study books and stuff. i always did really well in my spanish classes... what do you think?