Hi. DS2 has become such a handful lately, and DH and I are running out of ideas and motivation.
We have DS1 (7) and DS2 (5). Due DC3 in 6 weeks-not sure if this is an issue, as DSs don't appear particularly bothered about new arrival!
DS 1 was naughty at this age too, challenging. But he was remorseful after and really did try to change. He is now very well behaved.
DS2 has always been "cheeky". For example quite lazy, likes to demand you get him drinks etc. Leaves his clothes lying around, throws himself on floor crying if asked to get himself dressed etc. Lately he has become impossible. If he does not get his own way he goes mental. We do time out, put him on the stairs. He will wreck the place. Take pictures off walls and break them, throw stuff all over the place...I make him tidy it up when he calms down, but how can I stop it?
The latest is he has keyed my car! Twice! 
He is a model pupil in school, his teacher raves about him. But he finishes school half an hour before DS1, and I have started putting him in after school for this half hour as his behaviour is so awful. He will hit out at other kids etc.
DH is such a good disciplinarian, but he is struggling. DS2 just doesn't seem to care one bit! His apologies are just lip service.
DS1 has always been negative about DS2. DS1 has HFA, he struggled to "share" his life with DS2. They share a room since Spring, and it seemed to help, but now they are just bickering and fighting all day long. Over everything and anything. They cannot share breathing space. DS1 often says he wished DS2 was dead. I'm convinced this has had an effect on DS2-how could it not?! But when we are away or anything they buddy up no problem. And would stick up for each other when out.
Sorry this is so long!
Just need advice on how to get DS2 to calm down, stop stropping over everything, stop hitting, throwing and start to think about others a bit more.
Thanks if you got this far.
Just have no idea how I'm going to cope when DC3 is here.
Oh, and he picks his ruddy nose morning, noon and night! Gah!!!