Help: Gnarly Gnoises

Hi Everyone,

Have had an interesting development on my MY99 2.5RS over the last couple of days. I was driving on some gravel roads on the weekend and my car started to make an odd noise. It sounded like a rock caught between the wheel and the caliper, a sort of metal on metal type of squeal. But it didn't go away, and it wasn't very loud (not audible from outside the vehicle). When I got home I pulled the wheel off (passenger side front) and check, there wasn't anything caught in the calipers or anything and there was no sign of any rock that might have fallen out of the wheel. The noise is dependent upon engine speed, it doesn't make the noise under braking at all. If you lift off the gas the car sorta slows making the noise and then stops as the revs fall. This noise now seems to be accompanied by a severe vibration when the engine is winding up (but once again not with revs falling). The vibration is quite noticable through the floor pan of the vehicle. I'm also starting to get a nice "thunk" sound when I shift. Anyone have any ideas what this might be? I'm going to take the car back to the dealer to get them to look at it but I want to have some idea what the cause might be first.

Thanks in advance for all your help.

Regards,

Warren