If it is a rare car you could commit a felony and re body the car by putting the tags on another shell( Big NO NO ) I am certain it happens a lot with chevelles.....not saying it is ok just saying it happens...OR you could clip it at the windshield posts and DOOR JAMS and retain the factory cowl and numbers.....so technically it is the same rare car even though it isn't....but if it isn't anything special compared to the donor car I wouldn't bother.
example LS-6 chevelle vs a plain Jane Malibu.
jmo
I never have been fortunate enough to hang new OEM Quarters,so I don't have any experience to compare to, but I've used re pops on a couple cars that fit well. jmo