@FOUND SOUL,
Apparently he was with his girlfriend for 7 years but the relationship was in trouble, hence the purchase of the "two" cars, one of which had been delivered 3 days before the crash.
Also that he may have been bullied, that he grew up with planes all over his wall and dreamed of being a pilot but whilst waiting took a lesser job and was bullied as a result.
I don't think it was depression either. Rather, rage built up and perhaps knowing that he can't be a pilot hence, ripping up the Medical note, girlfriend perhaps on the verge of leaving him, eye sight, a lot of things but anger and rage and suicide as I said, in what he loved the most doing what he loved the most and not giving a damn about "people", humans, their lives in the process. An act of evil.