Sorry Tony, (and Rob) I guess my signature line just bit me on the arse.
I agree that the problem was really the Forester facia cover being slightly curved. I was trying to flush mount the empeg as I felt having the the front panel protruding was unsightly. Anyway, for a first timer my "dremmelising" of the fasia cover wasn't too bad. It is good to have the empeg firmly mounted and neat and tidy at last. Some pictures are available here.

In order of appearance my car audio is :
The empeg; green MK I 6GB
The Amps; Alpine V12 MRVF305 for front and rear doors
Alpine V12 MRVF501 in bridge mode for the rear sub box
The speakers; Alpine SPR175A in front and rear doors
JL Audio CS212R Sub box in the cargo area (2x 12")



PeterH
" 'tis better to be silent and thought a fool than to speak and remove all doubt"