Hiya, just returned from a weekend in Norfolk, and spotted not just one, but two G4s on my way home.
First, a naked RR, too quick to see if RRS or Vogue, but think it was a Vogue, no chance of spotting the reg. Completely dekitted, with no logos or anything. Just had enough time to wave, and got a response too. That was around 2ish today on the A505 between Royston and Duxford.
Second, fully kitted D3, unable to get reg. so no idea if a 2006 or 2009 vehicle. I don't think you spotted me as traffic was dense. Heading northbound on the M25 just after J15 the M4, you where in the middle lane, me the fast lane, so might have spotted me, around 3ish today.