Can you pop out a dent that has been repaired with bondo?

The top of my car has developed a dent in the top, almost like someone dropped a bowling ball on it. I ran a magnet across the skin and it's apparent that it's been repaired in the past with Bondo. I have no idea how it happened but I suspect that the bondo may have "sunk", if that's possible.

It's about 16" across and maybe 1/4" deep. Barely noticable but it's there. I'm reluctant to bang on it from underneath as I'm afraid that I could crack the paint.

I took the car to a Painless Dent repair shop and they want over $800 to fix it. I'd rather put that money towards a new transmission as I could live with the slight dent but if there's a way I can fix it myself I'm open to ideas.

Thoughts?