I was once on the old 2 lane bit of the M1 south of Luton heading in the rush hour to London.
A twat in an XR2 was weaving his way up the lanes. Inevitably he hit a lady in Capri. She spun & all hell broke loose as we tried to stop. She was in a state of total shock. The XR2 guy was grinning like an idiot and blaming her. The police arrived & he lost his smile as we witnesses all told what we saw.
Definitely a clean under wear moment.