Chart added to motor sign (9)
I believe the answer is:
autograph
'sign' is the definition.
(I know that autograph is a type of sign)
'chart added to motor' is the wordplay.
'chart' becomes 'graph' (I've seen this in another clue).
'added to' means one lot of letters go next to another.
'motor' becomes 'auto' (auto or automobile means a car).
'graph' put after 'auto' is 'AUTOGRAPH'.
(Other definitions for autograph that I've seen before include "a collector's item perhaps" , "(Celebrity's) signature" , "Handwriting" , "(Celebrity) signature" , "Sign" .)