Expensive car: BMW’s agreed with British newspaper (not half) (6)
I believe the answer is:
jaguar
'expensive car' is the definition.
'jaguar' can be an answer for 'car' (I have seen 'posh car' mean 'jaguar' so perhaps 'car' could also mean 'jaguar'). I am not certain of the 'expensive' bit.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for jaguar that I've seen before include "Big cat of tropical America" , "Fast car and savage wild cat" , "S.Amer. wild cat" , "Wild cat from S America, or fast car" , "Spotted feline and prestigious car" .)