My ff has started feeling a vibration or judder at low speeds and medium speeds - I don’t think it’s drive train related as it is still felt in neutral coasting.. any idea where to start looking? Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Tyres/ wheels would be where I'd start.

Get them off and rebalanced? Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Could be your rear diff bushes  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

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To be honest it could be and one of the front ones needs doing at some point at mot they said they will need doing at some point but won’t cause issues at the moment which was a few months ago. Is judder what you’d expect if that was the case? It appears slowly less noticable the faster you go 30 and below are worst. Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Turned out to be a bubble on the inside of a rear tyre! Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF