Got it!

I watched from the kitchen window as a young Thrush tussled with a snail it had found. It shook it and shook it, began to extract the snail from inside the shell. Then at last it had released it, threw the shell away and took the inside away to enjoy at leisure . . . under the car! 

We have seen adult Thrushes use a stone to crush the shell, but this young one had yet to learn that technique. It was successful nevertheless and we are one snail less in the garden.