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'm not certain of the 'expensive' bit.
I don't understand how the rest 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" .)