I had a couple of rides in a 6R4 - a chap had one at the gun club I used to shoot at with my dad. It still had the timing equipment etc. It was utterly ferocious and you had to wear ear defenders as the engine was literally behind your head! He later crashed it into a tree in his back garden.
I remember watching a "Metro Superchallenge" race at Donington Park in 1988, supporting the BTCC. It was a circuit stage of a mixed format championship but watching them take a shortcut over gravel trap onto the grand-prix loop made it look more like rally-cross! Maybe if F1 allowed this sort of behaviour it would be nearly as exciting!
To complete the historical loop, the XJ220 was originally conceived by the Jaguar 'Saturday club' from group B regulations in the 80's.
It became my job in the early 90's to develop a road car from it. The race version of that car went on the finish first in class at Le Mans in 1993.
Something no other Gp B car ever did!
So it is fitting in a way that it should be honoured with a Martini livery, sported by many other Gp B cars.
Two huge development generations later, the engine from the 6R4 would power the production XJ220!