Actually, it is not the first scene of the film, but it is the one that sets the story in motion. I've always found it to be a rather strange moment, as it never fully connects with the rest of the plot. There are only two elements I take away from it: first, Kyla's appearance as a witness to Diane's accident; and second, the possibility that it serves a metaphorical purpose. In other words, it may not be intended to advance the narrative, but rather to function as a visual metaphor for the audience. This is exactly what happens in Punch-Drunk Love (by PTA), where the opening crash has little to no impact on the plot and instead plays a symbolic role.

I find this interpretation even more convincing because, in the following sequence, we see Diane at Steve's reform school without a single injury and having arrived without any apparent difficulty despite the condition of her car.…