You're quite right, Brian. I was thinking about Dent King when I replied. I've edited my reply accordingly. I have no experience with the Ding King tool. No wonder there's trademark lawsuits over seemingly harmless names. The bridged multi-suction cup tool looks like the ultimate refinement of the old bathroom plunger dent puller technique. If you got caught in a golf ball sized hail storm and didn't have insurance then this little tool might be just the ticket.

If the dent has stretched or creased the metal (and it doesn't take much) then a suction dent removal will not by itself be overly successful. However, it may enable you to pull a dent out so you can carefully work it back to surface level with a soft pointed mallet. If the dent won't come out properly or the paint is broken then you'll need to do a traditional repair using a slide puller, hammer, fill, sand and prime. BTW, just as with drywall seaming, you can tell a professional autobody job from an amateur job by the amount of filler used. I'm usually the latter in both regards. A purist with access to the back of the panel will use no filler at all.