We have bought a 1990 CRX which has rear panels and wiring designed for speakers. Some car audio websites say the standard rear speaker for this car is a 6 1/2 inch. But it obviously needs an adapter to hold a round speaker, as the holes and existing plastic brackets behind the trim do not form a 6 1/2 inch circle. Our Honda dealer could not find any rear brackets in his catalogue. The CRX and regular Civic has a support bracket in the front door for speakers- can anyone suggest how we can find one for the back that will not involve a lot of redrilling of holes?