I saw something yesterday afternoon that had me rolling on the floor laughing my duck off and I still haven't stopped giggling about it.
I'd been to the shops, was on my way home and had just gone past a width restriction that is the type that's big enough to let an ambulance through when the bollard in the middle is released. With the bollard in place there ain't much space for vehicles to get through other than pushbikes, motorbikes, and on one occasion that I've witnessed - an incredibly cool original Mini Cooper.
So as I was saying, I'd just gone past the width restriction.
Behind the width restriction was a car; average size, certainly not a Mini or a Smart Ka, or any other variety of small car, just as I've said, average size so about 5ftish.
As I walked along the road I heard an incredibly loud grinding noise followed by a sort of crunch.
From the garage a little further along the road I heard a bloke call out "Oh my god!"
I looked back and saw to my amazement that the average sized car had tried to get through the obviously smaller than the average car sized gap of the width restriction.
Not quite believing that anybody could be so stupid as to attempt such a trick I dashed back just as the passenger (a woman) was getting out of the car and asked what had happened and was everybody alright?
She looked at me with a resigned expression and replied that yes, everyone was fine, just that her husband had tried to get through the gap.
The husband at this point got out of the car and scurried over to pick his bumper off the floor and try to re-attach it to the car.
I couldn't help but laugh out loud and say that hopefully he'd learnt not to do it again.
The poor wife just smiled wanly at me before glaring at her husband who had turned red enough to rival a traffic light.
I still can't stop giggling when I think about it.
What a prat.
(Photo taken while trying not to get seen by driver, so sorry about quality.)

So, what's the most stupid thing you've seen another driver do?