I have a persistent rattling behind/underneath the drivers dashboard on my 2004 Charade.

It only rattles on certain road surfaces, but it can be really noisy. All my mates can hear it but when I take it to be looked at, the Daihatsu garage claim they can never hear anything...despite me telling them exactly where to take the car....

I'm really fed up with it. Also the boot has started rattling now and is a little loose.

I love the car apart from the rattles, advice anyone????
Please!!