not strictly true argo,
i keep on writing to the council about speed bumps. Not all of them, as in bolton near work the are full sized sleeping policemen things and the car doesnt ground them.
Its those square ones. down the road from me, they are narrow enough to fit in a stilos track, and high enough to smack a slightly loose undertray, and eventually smash it to smithereens, as above. And this is at standard height. and im not the only one having problems.
They only slow me down in the stilo because the car cant get over them without conact, but the saxo will fly over them, infact the faster you go the less you feel. So all the big cars, (stilo, vectra, jag s types) get stuck and slow down, whilst all the little insurance friendly motors can whip over them.
I tried driving ove them with one wheel, and it buggered the tracking. I been on about them for years. There used to be a proper sump smasher about 5 miles from here, where the busses going over it had worn grooves eitherside of it so cars dropped in it as the road collapsed. I hit it in the ibiza and beached more or less. on looking at it there were oil spills after it and pools of oil at the side of the road. onths later still wasnt fixed!