Have YOU Run 5x100 and had Failure First Hand?

My 64 Valiant had 5x100 steel wheels off some import on the rear when i bought it. I suspect they weren't on the front too because of the hub thing. I couldn't keep the lug nuts tight, they would loosen up over about a week or so of driving 45 miles a day. Not a problem for me who recognized what that funny vibration was but I got some of the right wheels on as quick as I could afford it.