Just tonight my Ford Focus 1.6 Ghia 2001 developed a fault by which there was a slight rumbling at low speeds. In 1st and 2nd gear especially, mostly when turning. Don't think it's necessarily engine or exhaust directly. May just be the housing or something like that. Had a new one put in Mar 2011. Any tips as to what it could be as there's nothing very obvious looking underneath the car. Bit annoying as I've spent nearly £1000 on it since Nov 2010. Like to be foreknown before taking it to my garage.