Thanks all for the help guys. GoPro is a great idea as well. My lad wants one of those, he may have to wait a bit longer!
So, I spent an hour this morning looking in the "luggage" area.
Took my stuff out of the boot. Took all the tools and jack etc out of the storage area.
I loosened the spare wheel tensioner and re-tightened it.
The tooltray/box did not have the two plastic trim push fasteners, so had room to move. I replaced these to prevent any movement.
Some of the tools were a loose fit in their moulded places so I packed them slightly with some pieces of cloth. The jack when in place was slightly opened against its packing, again to prevent movement.
Made sure the rear centre fold down console was securely locked on its retaining clip.
Closed the lids and took it along my unmade up road, and all I can now hear is a very slight squeeking from the rear seats, leather on leather. I would expect that.
As I changed several things at the same time, can not tell what was the cause, but suspect the tools or the tool box moulding. I am just happy that the irritation has stopped, for the moment at least.
Allways felt it was not a suspension noise, but still pleased it did not result in having to replace the rears.
Thanks again for the suggestions.
Just to say, 1800 miles across France towng a vintage car on a trailer was a joy. The car was so comfortable as has been reported on other postings, gave on average 20-21 mpg.
Using the cruise control had the car changing gear a lot on inclines so I suspect turning it off resulted in better mpg and a more relaxing drive, at the cost of only a slight increase in journey time.
Great car,
Regards
David D