At first I was sure he didn't do it. Now I've rewatched part of the episode and I don't know. He's really odd looking in Carrie's office but it could be that he's just overwhelmed. There are some things to consider regarding motive:
I think too the more you look at it the more that it points to Brody. I mean if Brody didn't do it that means that at some point terrorists put a bomb in his car. And then somehow (unless there is a mole) terrorists snuck onto CIA property, broke into a car and then moved it to right in front of a main building (all without getting seen). It also means Brody is in one sense the luckiest man alive (because if he didn't do it then it means the terrorists wanted to kill him too)and the only thing that saved him was that he decided to get up in the middle of a memorial service, sneak out and go have sex with his mistress inside her mentor's office.
Now if he did do then it becomes a lot more likely. It means a bomb wasn't planted on the car without his knowledge (a bomb that big would probably take some time to install in a car. I would imagine it would also be heavy enough to be noticeable when you drive). It means the car wasn't broken into because he moved it. And it means he knew when to get up and leave because he knew the bomb was going to go off. To me all points to him knowing about it. Although I am not sure he knew that the video was going to be released.