Tested 2 other R type (different years)= same result
The car has an OEM setup that it's too soft for european sporty drivers (confirmed by Jag in Rome, this it's the reason they didn't sell too much in Italy)
Checked shocks and they are OK, bushings are OK
I get answer, from Bilstein and different tuners in Europe, that confirms the too soft OEM setup for driver used to other sporty coupes (BMW MERC AUDI EU models)
I choose the way to move to coilover setup or custom made setup from Bilstein or Tein (my tuner works with these two for race)
We do not drop the car more than 1 or 2 cmts
I will keep you informed

 

Salt on street destroyed and rusted the rear sway bar
Taking our the rear bushing (destroied) we found a really rusted sway bar
We ordered a new one, we will keep you informed on improovement