Since explosives have a high immediate damage they negate the majority of DR. I save my explosives for boss/legendary fights and they are always over very quickly, too quickly in some respects.
Of course, it works both ways - especially In terms of cars. During a fire fight I do give cars a wide berth but sometimes just forget. Next thing I know I'm having to go back to my last save because I stood next to a 200yr old wreck that seems to have the same explosive power as a mini nuke.
What do yo guys think? Does explosive damage needs to be tweaked?