Panel in vehicle by which I’m struck! (9)
I believe the answer is:
cartouche
'panel' is the definition.
(Ancient Egyptian tablet or panel)
'vehicle by which i'm struck' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'by which' means one lot of letters go next to another.
'i'm struck' becomes 'touche' ('touche' is said after being struck when fencing).
'car'+'touche'='CARTOUCHE'
'in' is the link.
(Other definitions for cartouche that I've seen before include "Panel" , "Ornate frame around an inscription" , "Carved decoration in the shape of a scroll" , "ornamental tablet" , "case of bullets" .)