Car has developed a "buzz" vibration which seems dependant on engine power. I think it is coming from the back, but difficult to locate. Not there all the time, comes and goes - sometimes slight, othertimes quite strong.

Not wheel bearings - quiet rolling with clutch down, any speed. Tyres are Dunlop SP Sport 01 (same from when I got car)

Possibles ?

loose baffle in exhaust ?

Haldex clutch ? (due for oil change)

Propshaft out of balance ?

something vibrating with increased power ?

Hoping that it is something "silly" and not expensive !!

If youre car is a facelift and has 2 zone climate it "could" be the temperature control rings vibrating; my vRS does this; being a CR diesel it vibrates more than the petrol would at certain revs. Drives me nuts as theres technically nothing wrong with the car.

Otherwise sorry no idea.