Ram, potentially, indicator of 50s Ford car (4,2,3,6)
I believe the answer is:
sign of the zodiac
'ram potentially' is the definition.
(I know that Aries is a sign of the zodiac)
'indicator of 50s ford car' is the wordplay.
I cannot really see how this works, but
'indicator' could be 'sign' (I've seen this before) and 'sign' is located in the answer.
'of' could be 'o' and 'o' is present in the answer.
'ford' could be 't' and 't' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for sign of the zodiac that I've seen before include "old Ford car's indicator?" , "Scorpio maybe" , "house" , "Maybe Leo" , "lion, say" .)