When I push the car hard and have my foot on the ground (which frequently happens ) I get a metaly type rattle between 3000 - 4000 rpm. I think I read on the old Mazda site that there was a type of bracket on the exhaust that can work loose. Does anyone have any suggestions?
It might also possibly be the induction kit. It is made by Ractive and I haven't seen any other cars on the site with one like it...Does anyone know what they are like or should I just ditch it?

If it happens in every gear, and only when you put your foot down, it might be the same as i'm getting, which sounds like 'pinking' or pre ignition (does sound like a metalic rattle). If this is the case, then the timeing needs adjusting, have you changed fuel type or octane recently?

Thats the sound - a metallic rattle. \over the past week or two it seems to have died off though :P

I just got it sorted. I gave my air filter in the air induction a good clean with a toothbrush and then used the air at a garage to low out most of the dust. She is flying now!