Another vote for pancake
I have a Smith 66-1 with a 4 inch barrel. I am not a big guy at only 5'6" and I can carry it with a Fobus pancake under a t-shirt without much printing if it is a loose t-shirt. I did this last weekend and my buddy didn't even know I was carrying. The key is to get an actual "gun belt" as mentioned earlier. I have tried "heavy" belts, but they don't work because they really aren't stiff enough. As for wearing it in a car, I have no problems, you just may need to adjust it when you first get in. I, like many people, have a back pack full of holsters I have tried. Right now, the Fobus pancakes are working for me. I have one for each of my handguns and when I go to camp and don't necessarily need to CC, this is what I use, although I do still wear them concealed without a problem.
I know you said you don't like IWB, and I respect that, but my everyday carry pieces are IWB. I have a Walther PPK/s with a Bianchi Type 100 and a Beretta 92FS Compact with a Cross Breed Super Tuck. Naturally the Walther is small, but I carry both at about the 4 o'clock, or appendix position and I have no problems driving, sitting at my desk working on the computer, and moving around during the day. I know you prefer revolvers, but just letting you know that Cross Breed and othes do make IWB holsters that may distribute the weight a little better and make that option more comfortable.