Get it close and use filler. Filler is your friend if used properly. Only use it on clean metal (or over epoxy primer...but that's another story). The metal must be roughed up a good bit so the filler will adhere. Moisture must not be able to get to the back side. Mix the filler properly, never add more hardener than the required amount. I'd suggest not going over 1/8" thick. The rt frt fender of my car was completely flattened when I got it in the 80s. It was worked out and skimmed properly with filler. Still looks good and no cracks almost 30 years later.
I've never had a problem pulling metal out of a dent with my hammer/dolly set but only with pushing it back in... the initial crease I had was pretty much where the metal is pushed out and on that side... so I was trying to push it in as if the crease was going into the car instead of out... didn't work obviously... ok I guess I'll pick up a plumbing torch one of these days and try that. here in Arizona I have to wait for it to cool down before I can use mix bondo other wise it starts to harden as soon as I get that perfect salmon color even when I mix it standing next to the car and go to apply it right there and I got a glob of bondo. thank you everyone.
will it still harden if I don't get that color? I know that's how they made it to know if you got it mixed right.
well a little update, I got tired of being gentle with it so I just placed a block of wood inside and used that 24oz framing hammer and went to town... looking better now... applied some bondo and I'm going to see where I'm at when I sand it down.
that bit just doesn't want to behave... I'm temped to take a sledge hammer to it so I can use bondo and make it look normal... don't know why this little problem is bugging me so much... but it's driving me crazy.
The one thing body work requires is a lot of patience if you don't have it save up your cash and take it to a pro
here are some more I'm in the process of covering it up until I learn a technique that might help, but it will always bug me... what if I used a cut off wheel and cut some relief lines in it than hammer and spot weld... I would prefer to just hammer it right.
Have you considered cutting out that section of the quarter, replacing it with a straight piece from another quarter and welding it in flush?
the hard part is finding a donor car that I can cut out a section... there are a couple salvage yards around here but I don't think they would allow me to cut a panel off... I could ask though. I'm sure a proficient body work person could fix this in no time.