I have just managed to install a pair of Vibe 5x7 speakers in the front of my GTV. I had to bend back two of the brackets on each speaker by 90 degrees but apart from that, they went in pretty easily.
After making a gasket out of blu-tak and spending an hour or so blocking up all the acoustic escape holes, I'm pleased with way she's sounding. There doesn't seem to be much I can do about the doors rattling in time with kick drums and bass. I guess that's the flimsy Alfa build quality for you!
What I am lacking is a pair of speaker grilles. The speakers which I replaced (think they were orig GTVs) just had a foam lining protecting the cones. I can't seem to find any in the usual places. Can anyone recommend a suitable set?