I think your post there Emma sums up most of the book. I don't mean I agree with your point that it's good, I mean I could have just read your post and not bothered buying the incredibly vague book. Like you say, most of the "juicy" stuff is left out and it's PR perfect.
I've got nothing against the man. People I know through racing that met him say he's very nice, and he's obviously very good at his job. And quite frankly, if someone came up to me and said, "write a quick account of your life so far, and we'll be able to get it out by Christmas and make enough money for you to buy your mum a couple of nice houses" I'd be reaching for the pencil myself!
I just didn't find it interesting, every page seemed to be "I went to race x and my dad helped me and i won/lost and that was cool/sad and I believed in myself and I love my family...." Still, you enjoyed it, so that's fine. People differ.
-As an aside, the next autobiography book I read was Slash's. By the time he was 22, he'd been a smack addict for 4 years, released one of the biggest albums in rock, got the clap, been a kleptomaniac and lived in a garage whilst sleeping with models. So remember kids, you CAN have a cool life by 22! (If not one that's particularly positive!)