Red motor belonging to me (7)
I believe the answer is:
carmine
'red' is the definition.
(I know that red can be written as carmine)
'motor belonging to me' is the wordplay.
'motor' becomes 'car' (informal term for car).
'belonging to me' becomes 'mine' (I've seen this before).
'car'+'mine'='CARMINE'
(Other definitions for carmine that I've seen before include "Crimson pigment" , "Bright red" , "Vivid red colour" .)