Having suffered stone damage to the radiator last year, I decided to have the original radiator re-cored. In order to prevent further damage in the future I decided to replace the radiator grille as well.
Every time I came back from a drive I noticed that there was a yellow powder on the seats and on the floor behind the seats. It seemed to be coming out of the headrests, which were not very solid.
My Caterham 7 reg R941GGY, aka 'IGGY'.