Last night I got a puncture (3rd one in the last 12 months) so I had to change my tyre. I loosened the bolts, jacked the car up using the e34 jack and started taking the bolts off, then out of the blue the car slipped off the jack! Luckily the wheel was not off yet so I bolted it all back and moved the car so it was jammed up against the kerb and did the whole lot again, I was extra cautious the second time, I even went across the road to confirm there was no gradient and that the jack was straight, this has happend to me once before so I'm extra careful when using this jack. As an extra precaution put the spare tyre under the car as soon as its high enough! now I know why they call it the widow maker.....