Cash wasted on relative in framework (7)
I believe the answer is:
chassis
'framework' is the definition.
(I know that chassis is a type of mounting)
'cash wasted on relative' is the wordplay.
'wasted' indicates an anagram.
'on' means one lot of letters go next to another.
'relative' becomes 'sis' (short for sister).
'cash' anagrammed gives 'chas'.
'chas'+'sis'='CHASSIS'
'in' is the link.
(Other definitions for chassis that I've seen before include "Main frame (of vehicle etc)" , "Car's structural framework" , "Car body" , "basic structure" , "Body framework" .)