Thanks for the great write-up and pics! It inspired me to swap out the crappy speakers in my Focus. I got some Focal 165 CA1's to stick in there. The flange of these speakers were just a little too big to sit perfectly within the flange of the stock speaker plastic, but they sat on the outer lip perfectly. Instead of tearing out the outer foam, I used an xacto blade to cut just outside of the speakers surround, leaving the outer foam in place to get a better seal. Also, instead of melting the plastic supports, I used some big wire cutters (snips would work too) and they just snapped right off the outer ring too. Anyway it was really easy with your guide! Here's a pic of an installed speaker:
The sound is much improved. Before I had to use some excessive EQ just to get it to sound right, but now I have the EQ flat and it sounds even better! Now all it needs is a good headunit, good amp, and a tight sub for it to be a great sounding system!