Hi guys. I'm seriously wound up now. Driving home from work today the car seemed fine for the first mile. After the first mile I have to climb this slight incline which is about half a mile long, as I started climbing the incline I was in second gear and as soon as I hit boost the car was juddering and shuddering around like it had no petrol left in it at all. Managed to get it up the incline without hitting boost again and as I got to the top of the incline the guy in front stopped to let someone out of a junction. I stopped too and the engine followed suit and just died. I started it and it wouldn't idle. Started it again and managed to ease it over into a bus stop. Popped the hood and called my mate Ronnie and he suggested it may be the plugs. After 5 minutes dropped the hood again and started the car. Car started and idled no problem. Drove home but kept it off boost. In the following 2 mile journey it still died twice. Got home and removed the plugs, nothing much wrong with them other than they were the wrong plugs and they were a little charred up but could have been cleaned. Changed them anyway with platinums and went out for a spin. Let it warm up to half temp on water and 72degrees on oil. Tried to boost it up a local dual carriageway and everything was fine, until it got to about 3000-4000revs at which point the car just starts miss firing and at one point it backfired so loud I swear I saw a flash of flame in my rear view mirror and there were no cars around. Any ideas what could be wrong? Please someone help me cos i'm fed up now. 3 things have gone wrong in 3 days of having the thing.