It sounds good, but I have to agree with Bry with regard to the farfetched part. I thought it was ridiculous enough that he got the A* after not going to school or revising, and now they have a 16 year old driving a car into the canal! I remember his birthday being in December, and the spoilers are probably in about October now, so it's not like he's going to be legal. How do the writers expect us to believe that he will make it to the canal without being caught or crashing?
David's justification of why he wanted to commit suicide will really be extremely hard to believe. He's worn the bullying record out, and he's left school now. And to do it for the reason he is; his sister marrying and him not being allowed to be there, or because it's Jason who climbed out of the toilet window the last time, are the reasons that someone would give and concequently be labelled a spoilt brat for.