I've found a lot of references to this product, but does anyone know the maximum mounting depth that will fit into the MSA rear speaker panel? This is for a '75 280Z. Thanks for any help!

Let's ask the obvious question, first. Did you call MSA and ask?

Haven't yet - looking for direct experience here. They recommend their own Retrosound 6x9s, as one might expect.

MSA offered no depth info. When my car's back, I'll fit the panel and measure, then post results. I can't be the only one with this question...

That depends..

do you have all the lines from teh tank to the evaporator back there? When I redid my evaporator tank, I no longer had room for 6x9's back there...

Here are pictures of mine in a 76, I don't have the measurements, hope this helps. speakers are 6x9.