I gotta go with Dukk on this one. A jigsaw is what I have used in the past and have gotten pretty good results.

 

I dont know your car, so probably this wont work for you, but last night I pulled the panel off my door and I THINK I can get away without cutting anything.

I have about an inch of space from the front face of the current speakers to the back of the door grill, so if I make a bracket / adapter 3/4" thick and mount the new component on it, it should pull the 6.5" new speaker far enough out to not need cutting metal. It looks like the diameter of the speaker cone, measured 3/4" down from the mounting flange is less than 5" which means the back part of the speaker will clear the current opening.

So my adapter will look oval in shape to use the existing mounting holes, with a larger round portion in the middle to accept a 6.5" diameter hole.

When I get a test one made from styrofoam I will post a pic to explain much better what I mean.

John

 

I can't fit a 6.5" in the door.
Designed for a 4.5" I was able to build a baffle out for my 5.25" . . . If I were to try and fit a 6.5" by building out, I'd need to build out more than an inch and that would look just stupid . . . so if I want 6.5" (and I do) I'll need to cut . . .

So from what I've been reading on here, I should talk to my friends with air tools and see if I can borrow something for a day . . . I've cut away parts of my car before with this Jigsaw, and I do NOT want to spend that much fiddling with a jigsaw, or swearing at the saw.

I hang out a fair bit with a mechanic for GM . . . I know he's got a vast tool collection. I'll ask if he has any air tools.