I'm trying to replace the 6X9 "subwoofers" (9 speaker system) in the rear deck of my 99 Park Ave with coaxials for rear fill. The factory amp is gone and I will be running them from the rear channels of my HU.

I've tried two brands, CDT and Boston Acoustics, and the speaker mounting holes just won't line up with the holes in the plastic package tray. Are the GM 6X9s different than the standard mounting centers? Has anyone successfully installed aftermarket speakers in the rear deck from underneath? If so, what brand did you use?

And now I've broken those silly plastic retainer clips, p/n 25641031, which I can't find anywhere except from GM for $4 each. Grrr. Anybody know of a source?

Thanks.

I think they mount from the top. I know my bonneville did

No, these mount from underneath. They are retained by 2 piece push-pins. They fit into a recess in the package tray.

i've replaced the GM 6X9s in every one of my cars that'* been equipped with them, they all used a standard mounting pattern.

however, i've never dealt with anything as complex as a 9 speaker system in a park avenue.

its a pita. ive got the same system. if they arent blown, id leave the stockers in. you have delco badged bose speakers in your car. that being said, i made some brackets for mine. lol.