Question about the ending. (Spoilers)

Did they have the accident on purpose, so that Scarlet could claim the insurance money?. And then it didn't work because they both died, right?. That part got me confused because Chad talked about taking his own life in order for Scarlet to get the insurance money.

I just want to make sure I understood this. The movie was good, especially because of the subject they chose (Chad's gambling problem). But the last 15 minutes or so were horrible.