Weird caring about a royal's fast vehicle (6,3)
I believe the answer is:
racing car
'vehicle' is the definition.
(I know that racing car is a car classification)
'weird caring about a royal's' is the wordplay.
'weird' indicates an anagram.
'about' becomes 'ca' (circa).
'a royal' becomes 'R' (common abbreviation e.g. RM - Royal Marine).
'caring' with letters rearranged gives 'racing'.
'racing'+'ca'+'r'='RACING-CAR'
'fast' acts as a link.
(Other definitions for racing car that I've seen before include "Vehicle designed for speed" , "Sports vehicle" , "Ferrari, for example" .)