Many years ago (A place far far away!!) my father got his car stuck on the slipway whilst trying to recover my 25 foot fisher.
He could not get traction to climb off the slip, so I told him to back down towards the slip so the boat engine was still in the water.
Bemused he did this!
I fired the boat engine up, pushing the car up the slip with his wheels spinning too.
WE didn't make it first try, so more throttle on the second go pushed us clear, but also shoved the boat 8 feet up the trailer and inches from the roof.
Ooops! I took 12 guys to bring the boat safely back onto the trailer rollers!!
Some of these pics bring back the "Oh S**t!!" factor.