Success with petitions for extra semester?

<p>Hi, I'm a transfer working out my curriculum and it looks like to do what I want to do (take a lot of science pre-reqs to get into cog sci/neuroscience) I will need another two semesters. The first (extra) semester will be given since I'll be at the 130 unit-cap, but not over. But the next one won't be since I'll be past the cap. So how much credence should I give to the idea that I'll be able to petition for an additional (sixth) semester? This would make my graduating unit total at 165. Should I just give up on the idea of taking all these extra (but seriously fascinating) courses so late in the game?</p>