Male only wants car that's big of its kind and aggressive-looking (4,6)
I believe the answer is:
stag beetle
'that's big of its kind and aggressive-looking' is the definition.
(large beetle)
'male only wants car' is the wordplay.
'male only' becomes 'stag' (as in a stag do).
'wants' says to put letters next to each other.
'car' becomes 'beetle' (Volkswagen Beetle).
'stag'+'beetle'='STAG-BEETLE'
(Other definitions for stag beetle that I've seen before include "something some folk find creepy" , "Large insect with branched mandibles" , "Six-footer" , "Insect with antler-like jaws" , "Horny little creature" .)