If I'd done any damage (and I'm probably more capable of determining the likelyhood of hidden damage etc than many) then yes, but if I'd left NO damage at all I'd not. Even if I'd just scuffed the paint a little I'd own up, because I hate the miserable sods who damage my car and drive off without saying a thing.
That said, with many of the large 4x4's its fairly easy to hit things and have absolutely no idea you have. We had an old rangey and I reversed it (very slowly and carefully) into a plastic-coated steel post buried in the concrete in a carpark. I had no idea I'd flattened it at all until I spotted the marks on my bumper and went back to check, it hadn't made a sound or anything.
You have to remember it's not how YOU value your car or cars in general, its basic respect for other peoples property regardless of whether you think "its just a car, they get scrapes". I actually know someone who now has a criminal record for driving away from such an impact after the owner spotted them from 3 floors above and took their reg number. They were charged and prosecuted, IIRC, with leaving the scene of an accident.