Hmmm... I've noticed something along these lines too - in my March 2004 MINI ONE.
It doesn't sound like anything's going particularly wrong, but it does sound like the car is developing a new noise as it ages. I couldn't track it any more precisely than the driver's footwell - as normally when I notice it, I'm doing 45-60mph so it would be insane not to be focused on the road.
If anyone has any tips for quietening it down or silencing it, I'd also be interested!
Many thanks in advance,
Andrew.
