Okay, got to own up, I think the P6 you saw that day is probably mine, it is a 3500 auto in tobacco leaf (of course) and the day in question was a pleasant sunny day so I took the opportunity to have a little run (to Wentworth garden centre on this occasion) I live at Sheffield Lane Top so I frequently drive down Barnsley road and I have noticed a lunar grey P6 parked in front of a shop window (set back from the slightly), I keep promising myself to call in one day when I see the said P6 just to find out who owns the second best car in the world (only kidding)
Just for the record I have owned my Rover for nearly 34 years now (can't bear to part with it) I had it restored in 2002 and now I only use it when the weather is reasonable, also I've been a member of the P6 ROC since about 1983.
Best Regards DAV8