Geneva car tax may be seen as excessive amount (12)
I believe the answer is:
extravagance
'as excessive amount' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'geneva car tax may be' is the wordplay.
'may be' indicates an anagram.
'geneva'+'car'+'tax'='genevacartax'
'genevacartax' with letters rearranged gives 'EXTRAVAGANCE'.
'seen' is the link.
Can you help me to learn more?
(Other definitions for extravagance that I've seen before include "Excessive spending" , "Excess" , "Profligacy" , "high consumption" , "Overspending" .)