We have a 10year old nissan micra and recently it has started making a rattling/clunking sound from undernesth the car, behind the drivers seat. My boyfriend thinks it is to do with the suspension, if it is how much approx. will it be to cost? and is it safe to drive with the rattle? It's been like it for a few weeks but hasn't got worse, but we couldn't book it in to a garage until today. Thanks x