Metra 82-4300 1" Depth Extender Pair

Being plastic in itself is not the problem. The problem is that they have a hollow cross-section which makes it impossible to chamfer the top inside edge which you need to do if you use them to install 6.5" speakers. I ended up stacking Neoprene rings between the speaker frame and these spacers so as to allow clearance to the inside diameter which is too small for 6.5" speakers. Metra should have made these available in two sizes. One for 5 to 5.5" and one for 6 to 6.5" speakers or made them with a 0.25" wall thickness on the top surface.

I have a 2003 VW Jetta and the brackets fit on with no fuss and the holes matched up like they where stock. The hardware that came with it was easy to do as well. Had to drill a hole though for the wire to come out but its high grade plastic so it worked fine.

This product is great the only step better would be to use a wooden version of this spacer