Is enthralled by weird architect's car features (15)
I believe the answer is:
characteristics
'features' is the definition.
('characteristic' can be a synonym of 'feature')
'is enthralled by weird architect's car' is the wordplay.
'enthralled by' means one lot of letters goes inside another ('enthral' can mean 'capture').
'weird' is an anagram indicator.
'architects'+'car'='architectscar'
'architectscar' with letters rearranged gives 'charactertics'.
'is' put within 'charactertics' is 'CHARACTERISTICS'.
(Other definitions for characteristics that I've seen before include "marks" , "features" , "Parts" .)